研究者総覧

鷹股 亮TAKAMATA Akiraタカマタ アキラ

所属部署名研究院生活環境科学系生活健康学領域
職名教授
Last Updated :2022/10/06

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プロフィール情報

  • 鷹股, タカマタ
  • 亮, アキラ

学位

  • 博士(医学), 京都府立医科大学

研究キーワード

  • 浮腫
  • 内皮機能
  • アンギオテンシンII
  • 骨格筋血流調節
  • 飲水行動
  • 体温調節
  • 体液調節
  • 摂食行動
  • 生体リズム
  • 女性ホルモン

研究分野

  • ライフサイエンス, 栄養学、健康科学
  • ライフサイエンス, 生理学
  • 人文・社会, 家政学、生活科学

経歴

  • 2007年, 9999年, 奈良女子大学 生活環境学部 教授, Faculty of Human Life and Environment
  • 2007年, 9999年, Professor, Nara Women's University
  • 2016年, 2016年, ジョン・ピアス研究所、イェール大学産婦人科学・生殖科学 客員教授
  • 2016年, 2016年, Visiting Professor, John B. Pierce Laboratory, and Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine
  • 2002年, 2007年, 奈良女子大学 生活環境学部 助教授, Faculty of Human Life and Environment
  • 2002年, 2007年, Associate Professor, Nara Women's University
  • 1994年, 2002年, 京都府立医科大学 第一生理学教室 助手
  • 1994年, 2002年, Assistant Professor, Department of Physiology, Kyoto Prefectural University of Medicine
  • 1991年, 1994年, ジョン ピアス研究所、イェール大学医学部 博士研究員
  • 1991年, 1994年, Postdoctoral Associate, John B. Pierce Laboratory, and Yale University School of Medicine

所属学協会

  • 日本繊維製品消費科学学会
  • 日本生気象学会
  • 日本栄養・食糧学会
  • 米国生理学会
  • 日本生理学会
  • The Japan Research Association for Textile End-Users
  • American Physiological Society

Ⅱ.研究活動実績

論文

  • 査読あり, その他, Nutrients, Endogenous Androgens Diminish Food Intake and Activation of Orexin A Neurons in Response to Reduced Glucose Availability in Male Rats, Akira Takamata; Yuri Nishimura; Ayano Oka; Mayuna Nagata; Natsumi Kosugi; Sayaka Eguchi; Hiroko Negishi; Keiko Morimoto, Sex steroids modify feeding behavior and body weight regulation, and androgen reportedly augments food intake and body weight gain. To elucidate the role of endogenous androgens in the feeding regulation induced by reduced glucose availability, we examined the effect of gonadectomy (orchiectomy) on food intake and orexin A neuron’s activity in the lateral hypothalamic/perifornical area (LH/PFA) in response to reduced glucose availability (glucoprivation) induced by 2-deoxy-d-glucose (2DG) administration in male rats. Rats (7W) were bilaterally orchiectomized (ORX group) or sham operated (Sham group). Seventeen days after the surgery, food intake response to 2DG (400 mg/kg, i.v.) was measured for 4 h after the infusion. The same experiment was performed for the immunohistochemical examination of c-Fos-expressing orexin A neurons in the LH/PFA and c-Fos expression in the arcuate nucleus (Arc). Food intake induced by glucoprivation was greater in the ORX group than the Sham group, and the glucoprivation-induced food intake was inversely correlated with plasma testosterone concentration. Glucoprivation stimulated c-Fos expression of the orexin A neurons at the LH/PFA and c-Fos expression in the dorsomedial Arc. The number and percentage of c-Fos-expressing orexin A neurons in the LH/PFA and c-Fos expression in the dorsomedial Arc were significantly higher in the ORX group than the Sham group. This indicates that endogenous androgen, possibly testosterone, diminishes the food intake induced by reduced glucose availability, possibly via the attenuated activity of orexin A neuron in the LH/PFA and neurons in the dorsomedial Arc., 2022年03月15日, 14, 6, 1235, 1235, 研究論文(学術雑誌), 国際誌, 国際共著している
  • 査読あり, 英語, Physiological reports, Estradiol replacement improves high-fat diet-induced insulin resistance in ovariectomized rats., Naoko Yokota-Nakagi; Sayo Omoto; Shoko Tazumi; Mizuho Kawakami; Akira Takamata; Keiko Morimoto, The role of 17β-estradiol (E2) in high-fat diet (HFD)-induced alteration of the protein kinase B (Akt) signaling pathway in ovariectomized (OVX) rats is unclear. Therefore, we examined whether chronic estrogen replacement restores HFD-induced impairment in insulin sensitivity by its effects concomitant with alterations in the Akt isoform 2 (Akt2) and Akt substrate of 160 kDa (AS160) phosphorylation in muscles of OVX rats. Nine-week-old female Wistar rats underwent ovariectomy under anesthesia; after 4 weeks, subcutaneous implantation of either E2 or placebo (PL) pellets was performed, and HFD feeding was initiated. Intravenous glucose tolerance tests were performed to assess insulin sensitivity. Following insulin injection into rats' portal vein, the liver and gastrocnemius muscle were dissected for insulin signaling analysis. We observed that HFD increased energy intake and body weight in the PL group; however, it was temporarily decreased in the E2 group. Adipose tissue accumulation was larger in HFD-fed rats than in normal chow diet (NCD)-fed rats in the PL group; however, this difference was not observed in the E2 group. HFD reduced insulin sensitivity in the PL group only. In vivo insulin stimulation increased Akt2 phosphorylation in the muscles of NCD-fed rats in both groups. In contrast, HFD affected insulin-stimulated phosphorylation of Akt2 and AS160 in the muscles of rats in the PL group but not in the E2 group. Our data suggest that E2 replacement improves HFD-induced insulin resistance, and this effect is accompanied by the alterations in the Akt2 and AS160 phosphorylation in insulin-stimulated muscles of OVX rats., 2022年03月, 10, 5, e15193, 研究論文(学術雑誌), 国際誌
  • 査読あり, 英語, Nutrients, Estradiol Replacement Improves High-Fat Diet-Induced Obesity by Suppressing the Action of Ghrelin in Ovariectomized Rats., Naoko Yokota-Nakagi; Haruka Takahashi; Mizuho Kawakami; Akira Takamata; Yuki Uchida; Keiko Morimoto, This study aims to investigate the effects of estradiol replacement on the orexigenic action of ghrelin in ovariectomized (OVX) obese rats fed with a high-fat diet (HFD). Four weeks after OVX at 9 weeks of age, Wistar rats were subcutaneously implanted with either 17β-estradiol (E2) or placebo (Pla) pellets and started on HFD feeding. After 4 weeks, growth hormone-releasing peptide (GHRP)-6, a growth hormone secretagogue receptor (GHSR) agonist injected intraperitoneally, induced changes in HFD intake, and c-Fos-positive neurons in the hypothalamic arcuate nucleus (ARC) were measured in both groups. The ghrelin protein and mRNA levels, as well as GHSR protein in stomach, were analyzed by Western blotting and real-time PCR. HFD increased energy intake and body weight in the Pla group, while it temporarily reduced these in the E2 group. GHRP-6 enhanced HFD intake and activated neurons in the ARC only in the Pla group. Furthermore, gastric ghrelin and GHSR protein levels were lower in the E2 group than in the Pla group, but plasma acyl ghrelin levels were similar in both groups. Our results suggest that E2 replacement improves obesity by inhibiting the orexigenic action of ghrelin via downregulation of ghrelin and its receptor in stomach in HFD-fed OVX rats., 2020年03月26日, 12, 4, 研究論文(学術雑誌), 国際誌
  • 査読あり, その他, Nutrients, Fluoxetine Mimics the Anorectic Action of Estrogen and Its Regulation of Circadian Feeding in Ovariectomized Female Rats, Yuri Nishimura; Kaori Mabuchi; Natsumi Omura; Ayako Igarashi; Megumi Miura; Nanako Mima; Hiroko Negishi; Keiko Morimoto; Akira Takamata, Our previous study demonstrated that chronic estrogen replacement in ovariectomized rats reduces food intake and augments c-Fos expression in the suprachiasmatic nucleus (SCN), specifically during the light phase. Here, we hypothesized that serotonergic neurons in the central nervous system (CNS), which have anorectic action and play a role in regulating circadian rhythm, mediate the light phase-specific anorectic action of estrogen, and that selective serotonin reuptake inhibitors (SSRIs) mimic the hypophagic action of estrogen. Female Wistar rats were ovariectomized and treated with estradiol (E2) or cholesterol by subcutaneously implanting a silicon capsule containing E2 or cholesterol. Then, half of the cholesterol-treated rats were injected with the SSRI fluoxetine (5 mg/kg) (FLX group), while the remaining rats in the cholesterol-treated group (CON group) and all those in the E2 group were injected with saline subcutaneously twice daily at the onsets of the light and dark phases. Both E2 and FLX reduced food intake during the light phase but not the dark phase, and reduced body weight gain. In addition, both E2 and FLX augmented the c-Fos expression in the SCN, specifically during the light phase. These data indicate that FLX exerts estrogen-like antiobesity and hypophagic actions by modifying circadian feeding patterns, and suggest that estrogen regulates circadian feeding rhythm via serotonergic neurons in the CNS., 2020年03月22日, 12, 3, 849, 849, 研究論文(学術雑誌), 国際誌, 国際共著している
  • 査読あり, 英語, The journal of physiological sciences : JPS, Endurance running exercise is an effective alternative to estradiol replacement for restoring hyperglycemia through TBC1D1/GLUT4 pathway in skeletal muscle of ovariectomized rats., Mizuho Kawakami; Naoko Yokota-Nakagi; Akira Takamata; Keiko Morimoto, Menopause is a risk factor for impaired glucose metabolism. Alternative treatment of estrogen for postmenopausal women is required. The present study was designed to investigate the effects of 5-week endurance running exercise (Ex) by treadmill on hyperglycemia and signal pathway components mediating glucose transport in ovariectomized (OVX) placebo-treated rats, compared with 4-week 17β-estradiol (E2) replacement or pair-feeding (PF) to the E2 group. Ex improved the hyperglycemia and insulin resistance index in OVX rats as much as E2 or PF did. However, Ex had no effect on body weight gain in the OVX rats. Moreover, Ex enhanced the levels of GLUT4 and phospho-TBC1D1 proteins in the gastrocnemius of the OVX rats, but E2 or PF did not. Instead, the E2 increased the Akt2/AS160 expression and activation in the OVX rats. This study suggests that endurance Ex training restored hyperglycemia through the TBC1D1/GLUT4 pathway in muscle by an alternative mechanism to E2 replacement., 2019年11月, 69, 6, 1029, 1040, 研究論文(学術雑誌), 国内誌
  • 査読無し, 日本語, 食と医療, 水分補給による熱中症予防の生理学的メカニズム, 鷹股 亮, 2019年07月, 10, 15, 22
  • 査読あり, 英語, The journal of physiological sciences : JPS, The effect of menstrual cycle phase on foot skin temperature during mild local cooling in young women., Yuki Uchida; Koyuki Atsumi; Akira Takamata; Keiko Morimoto, Japanese women can experience a sensation of cold feet in daily life. It is possible that this sensation of coldness in feet may be associated with female hormones, but to date the effect of menstrual cycle phase on the skin temperature (Tsk) of the foot during local cooling is unknown. We therefore examined Tsk and partial cutaneous blood flow in the foot during the follicular (F) and luteal (L) phases of the menstrual cycle in women experiencing local cooling. Tsk was measured in the toes and the dorsum of the left foot using infrared thermography, while cutaneous blood flow was evaluated in the big toe of the left foot using laser Doppler flowmetry (LDF), both at 28 °C. Mild local cooling (24.7 °C) was then applied for 30 min to the right foot. During cooling of the right foot, no significant differences in Tsk were observed between the F and L phases in either the toes of the left foot or the dorsum of the left foot of all subjects. However, cutaneous blood flow determined by LDF in the big toe of the left foot was greater in the F phase than in the L phase. These results suggest that the menstrual cycle phase did not affect Tsk in the foot, but it did affect cutaneous blood flow in the big toe during mild local cooling., 2019年01月, 69, 1, 151, 157, 研究論文(学術雑誌), 国内誌
  • 査読あり, 英語, American journal of physiology. Endocrinology and metabolism, Estrogen replacement enhances insulin-induced AS160 activation and improves insulin sensitivity in ovariectomized rats., Mizuho Kawakami; Naoko Yokota-Nakagi; Masami Uji; Ken-Ichi Yoshida; Shoko Tazumi; Akira Takamata; Yuki Uchida; Keiko Morimoto, Menopause predisposes women to impaired glucose metabolism, but the role of estrogen remains unclear. In this study, we examined the effects of chronic estrogen replacement on whole body insulin sensitivity and insulin signaling in ovariectomized rats. Female Wistar rats aged 9 wk were ovariectomized under anesthesia. After 4 wk, pellets containing either 17β-estradiol (E2) or placebo (Pla) were subcutaneously implanted in the rats. After 4 wk of treatment, the intra-abdominal fat accumulation was greater in the Pla group than that in the E2 group. Hyperinsulinemic-euglycemic clamp analysis and intravenous glucose tolerance test revealed that insulin sensitivity was significantly lower in the Pla group than in the E2 group. In addition, Western blotting showed that in vivo insulin stimulation increased protein kinase B (Akt) phosphorylation to a similar degree in the gastrocnemius and liver of both groups, but phosphorylated Akt2 Ser474 was enhanced in the muscle of the E2 group compared with the Pla group. Moreover, insulin-stimulated phosphorylation of Akt substrate of 160 kDa (AS160) Thr642 was observed only in the E2 group, resulting in the difference between the two groups. Additionally, AS160 protein and mRNA levels were higher in muscle of the E2 group than the Pla group. In contrast, E2 replacement had no effect on glucose transporter 4 protein levels in muscle and glycogen synthase kinase-3β in muscle and liver. These results suggest that estrogen replacement improves insulin sensitivity by activating the Akt2/AS160 pathway in the insulin-stimulated muscle of ovariectomized rats., 2018年12月01日, 315, 6, E1296-E1304, E1304, 研究論文(学術雑誌), 国際誌
  • 査読あり, その他, American Journal of Physiology-Heart and Circulatory Physiology, Blood pressure predicts endothelial function and the effects of ethinyl estradiol exposure in young women, Tessa E. Adler; Charlotte W. Usselman; Akira Takamata; Nina S. Stachenfeld, Hypertension, obesity, and endothelial function predict cardiovascular disease in women, and these factors are interrelated. We hypothesized that hypertension and obesity are associated with endothelial dysfunction in young women and that short-term ethinyl estradiol exposure mitigates this dysfunction. We examined flow-mediated dilation (FMD) responses before and during 7 days of oral ethinyl estradiol (30 µg/day) in 19 women (25 ± 5, 18–35 yr). We divided our sample into two groups based on two criteria: blood pressure and obesity. Women were divided into normal blood pressure (NBP; mean arterial pressure range: 78–91 mmHg, n = 7) and high blood pressure (HBP; mean arterial pressure range: 95–113 mmHg, n = 9) groups. We also stratified our subjects by body composition (lean: 18–31%, n = 8; obese: 38–59%, n = 9). We evaluated brachial FMD after two distinct shear stress stimuli: occlusion alone and occlusion with ischemic handgrip exercise. Obesity was unrelated to both FMD responses. Before ethinyl estradiol administration, the HBP group had blunted ischemic exercise responses relative to the NBP group (8.0 ± 3.5 vs. 12.3 ± 3.2%, respectively, P = 0.05). However, during ethinyl estradiol administration, ischemic exercise responses increased in the HBP group (12.8 ± 6.1%, P = 0.04) but decreased in the NBP group (5.6 ± 2.4%, P = 0.01). Standard FMD did not reveal differences between groups. In summary, 1) moderate HBP predicted endothelial impairment, 2) ethinyl estradiol administration had divergent effects on FMD in women with NBP versus HBP, and 3) enhanced FMD (ischemic handgrip exercise) revealed differences in endothelial function, whereas standard FMD (occlusion alone) did not. NEW & NOTEWORTHY We are the first to show that mild hypertension is a stronger predictor of endothelial dysfunction than obesity in healthy women without overt cardiovascular dysfunction. Importantly, the standard 5-min flow-mediated vasodilation stimulus did not detect endothelial dysfunction in our healthy population; only an enhanced ischemic handgrip exercise shear stress stimulus detected endothelial impairment. Estradiol administration increased flow-mediated dilation in women with high blood pressure, so it may be a therapeutic intervention to improve endothelial function., 2018年10月01日, 315, 4, H925, H933, 研究論文(学術雑誌), 国際誌, 国際共著している
  • 査読あり, 英語, Am J Physiol Heart Circ Physiol., Estrogen replacement attenuates stress-induced pressor responses through vasorelaxation via β2-adrenoceptor in peripheral arteries of ovariectomized rats., Tazumi S; Omoto S; Nagatomo Y; Kawahara M; Yokota N; Kawakami M; Takamata A; Morimoto K, We examined whether chronic estrogen replacement has an inhibitory effect on stress-induced pressor responses via activation of β2-adrenoceptor (AR) in peripheral arteries of ovariectomized rats. Female Wistar rats aged 9 wk were ovariectomized. After 4 wk, pellets containing either 17β-estradiol (E2) or placebo (Pla) were subcutaneously implanted into the rats. After 4 wk of treatment, rats underwent cage-switch stress, and, in a separate experiment, a subset received an infusion of isoproterenol (ISO) with or without pretreatment with the β1-AR blocker atenolol or the β2-AR blocker butoxamine. In addition, the isolated mesenteric artery was used to assess the concentration-related relaxing responses to ISO and the β1- or β2-AR mRNA level. The cage-switch stress-induced pressor response was significantly attenuated in the E2-treated group compared with the Pla-treated group. Pretreatment with atenolol reduced blood pressure responses in both groups. However, butoxamine enhanced the pressor response only in the E2-treated group, resulting in no difference between the two groups. In addition, the intravenous ISO-induced depressor response was significantly enhanced in the E2-treated group compared with the Pla-treated group. Furthermore, the difference in the depressor response was abolished by pretreatment with butoxamine but not by atenolol. In the isolated mesenteric artery, butoxamine caused a rightward shift in ISO-induced concentration-related relaxation in the E2-treated group. The β2-AR mRNA level in the mesenteric artery was higher in the E2-treated group than in the Pla-treated group. These results suggest that estrogen replacement attenuated the stress-induced pressor response probably by suppressing vasoconstriction via activation of β2-ARs in peripheral arteries of ovariectomized rats. NEW & NOTEWORTHY In this study, we show, for the first time, that estrogen replacement has an inhibitory effect on the psychological stress-induced pressor response through vasorelaxation via β2-adrenoceptors, probably due to overexpression of β2-adrenoceptor mRNA, in peripheral arteries of ovariectomized rats., 2018年02月01日, 314, 2, H213-H223, 研究論文(学術雑誌), 国際誌
  • 査読あり, その他, Frontiers in Endocrinology, S-equol Exerts Estradiol-Like Anorectic Action with Minimal Stimulation of Estrogen Receptor-α in Ovariectomized Rats, Yuri Nishimura; Kaori Mabuchi; Azusa Takano; Yayoi Hara; Hiroko Negishi; Keiko Morimoto; Tomomi Ueno; Shigeto Uchiyama; Akira Takamata, 2017年10月19日, 8, 研究論文(学術雑誌), 国際誌
  • 査読無し, その他, 実験医学, 摂食調節における性差と性ホルモンの役割, 鷹股 亮; 鷹股亮; 森本恵子, 2017年, 35, 6, 945, 950
  • 査読あり, 日本語, 日本生気象学会雑誌, 日本生気象学会, 体液調節と女性ホルモン, 鷹股 亮, 2017年, 54, 2, 57, 64
  • 査読あり, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Effects of estrogen replacement on stress-induced cardiovascular responses via renin-angiotensin system in ovariectomized rats, Shoko Tazumi; Naoko Yokota; Mizuho Kawakami; Sayo Omoto; Akira Takamata; Keiko Morimoto, 2016年11月, 311, 5, R898, R905, 研究論文(学術雑誌)
  • 査読あり, 英語, EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY, Target intensity and interval walking training in water to enhance physical fitness in middle-aged and older women: a randomised controlled study, Shuichi Handa; Shizue Masuki; Takuya Ohshio; Yoshi-ichiro Kamijo; Akira Takamata; Hiroshi Nose, To determine the target intensity for fast walking during interval walking training (IWT) in water for middle-aged and older people to enhance physical fitness. Thirty-one women [59 +/- 5 (SD) years old] were randomly divided into two groups: IWT on land (LG, N = 15) and in water (WG, N = 16). All subjects were instructed to perform a parts per thousand yen6 sets of fast and slow walking for 3 min each in a day, a parts per thousand yen4 days week(-1), for 8 weeks, at an intensity 35 % higher than the oxygen consumption rate at the gas exchange threshold (O-2GET), with a subjective feeling of 16-18 points of the Borg scale during fast walking in each condition. Before and after IWT, we measured O-2GET, peak aerobic capacity (O-2peak) by graded walking and cycling tests on land and isometric knee extension (F (EXT)) and flexion (F (FLX)) forces. Before IWT, the O-2GET for walking in water was 14 % higher and the heart rate (HR) at a given O-2 was similar to 10 beats min(-1) lower (P=0.001) than on land. During IWT, subjects in both groups performed IWT for similar to 4 days week(-1) (P > 0.9) with a 14 % higher fast walking intensity in WG than in LG (P < 0.05). After IWT, the O-2peak and O-2GET for cycling, F (EXT) and F (FLX) increased more in WG than in LG (all, P < 0.05). Walking in water elevated O-2GET and decreased HR at a given exercise intensity in middle-aged and older women, which enabled them to perform exercise at a higher metabolic rate than on land due to improved subjective feelings, which, for these subjects, resulted in greater gains in physical fitness., 2016年01月, 116, 1, 203, 215, 研究論文(学術雑誌)
  • 査読無し, その他, 繊維製品消費科学, ヒトをはかる16話(その14)循環機能をはかる, 鷹股 亮, 2015年, 56, 8
  • 査読あり, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, Involvement of orexin-A neurons but not melanin-concentrating hormone neurons in the short-term regulation of food intake in rats, Yuri Nishimura; Kaori Mabuchi; Sayumi Taguchi; Saori Ikeda; Eri Aida; Hiroko Negishi; Akira Takamata, 2014年05月, 64, 3, 203, 211, 研究論文(学術雑誌)
  • 査読無し, 日本語, 繊維製品消費科学, 一般社団法人 日本繊維製品消費科学会, ヒトをはかる16話(その9)代謝量をはかる, 鷹股 亮, 2014年, 55, 10, 722, 723
  • 査読無し, その他, 繊維製品消費科学, ヒトをはかる16話(その10)酸素消費量をはかる, 鷹股 亮, 2014年, 55, 723
  • 査読あり, 英語, Contrast Media and Molecular Imaging, Mn-citrate and Mn-HIDA: Intermediate-affinity chelates for manganese-enhanced MRI, Yoshiteru Seo; Keitaro Satoh; Hironobu Morita; Akira Takamata; Kazuto Watanabe; Takashi Ogino; Tooru Hasebe; Masataka Murakami, In this study we investigated two manganese chelates in order to improve the image enhancement of manganese-enhanced MRI and decrease the toxicity of free manganese ions. Since both MnCl2 and a low-affinity chelate were associated with a slow continuous decrease of cardiac functions, we investigated intermediate-affinity chelates: manganese N-(2-hydroxyethyl)iminodiacetic acid (Mn-HIDA) and Mn-citrate. The T1 relaxivity values for Mn-citrate (4.4 m m-1 s-1) and Mn-HIDA (3.3 m m-1 s-1) in artificial cerebrospinal fluid (CSF) were almost constant in a concentration range from 0.5 to 5 m m at 37 °C and 4.7 T. In human plasma, the relaxivity values increased when the concentrations of these Mn chelates were decreased, suggesting the presence of free Mn2+ bound with serum albumin. Mn-HIDA and Mn-citrate demonstrated a tendency for better contractility when employed with an isolated perfused frog heart, compared with MnCl2. Only minimal changes were demonstrated after a venous infusion of 100 m m Mn-citrate or Mn-HIDA (8.3 μmol kg-1 min-1) in rats and a constant heart rate, arterial pressure and sympathetic nerve activity were maintained, even after breaking the blood-brain barrier (BBB). Mn-citrate and Mn-HIDA could not cross the intact BBB and appeared in the CSF, and then diffused into the brain parenchyma through the ependymal layer. The responses in the supraoptic nucleus induced by the hypertonic stimulation were detectable. Therefore, Mn-citrate and Mn-HIDA appear to be better choices for maintaining the vital conditions of experimental animals, and they may improve the reproducibility of manganese-enhanced MRI of the small nuclei in the hypothalamus and thalamus. © 2012 John Wiley & Sons, Ltd., 2013年03月, 8, 2, 140, 146, 研究論文(学術雑誌)
  • 査読あり, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, Diffusion of manganese chelates in the rat brain measured by T-1-weighted MRI, Yoshiteru Seo; Akira Takamata; Takashi Ogino; Hironobu Morita; Masataka Murakami, 2013年, 63, S137, S137
  • 査読無し, その他, LISA, 低体温と全身麻酔と代謝,そして腎機能─低温環境で体温維持に働く非ふるえ熱産生 全身麻酔は褐色脂肪組織などの熱産生を阻害する., 鷹股 亮, 2012年, 19, 18, 23
  • 査読無し, その他, 月刊食生活, 健康と水, 鷹股 亮, 2012年, 106
  • 査読あり, 英語, J Phys Fitness Sports Med, The Japanese Society of Physical Fitness and Sports Medicine, Modification of thermoregulatory response to heat stress by body fluid regulation., 鷹股 亮; Takamata A, The thermoregulatory system interacts vitally with the body fluid regulatory system. Thermoregulatory response during heat stress, such as sweating and cutaneous vasodilation, stimulates body fluid regulatory response by elevating plasma osmolality and reducing central blood volume. Isotonic hypovolemia, or baroreceptor unloading, and plasma hyperosmolality, in turn, inhibit thermoregulatory response to heat stress, suggesting that body fluid regulation is given priority over thermoregulation. On the other hand, osmoregulatory vasopressin secretion and thirst are augmented by elevated body core temperature. Heat acclimation enhances thermoregulatory response to heat stress. Adaptation of the body fluid regulatory system, such as increased plasma volume and reduced osmotic inhibition of thermoregulatory response, is possibly involved in the mechanism for the enhancement of thermoregulatory response to heat stress by heat acclimation. In this review, we discuss the interaction between body fluid regulation, especially osmoregulation, and thermoregulation mainly in humans., 2012年, 1, 3, 479, 489
  • 査読あり, その他, 発汗学, 温熱発汗に及ぼす体液調節系からの抑制, 鷹股 亮, 2012年, 19, 2, 56, 59, 研究論文(学術雑誌)
  • 査読無し, その他, 体育の科学, 摂食/体重コントロールと性ホルモン, 鷹股 亮, 2012年, 62, 12, 942, 945
  • 査読あり, 英語, BRITISH JOURNAL OF NUTRITION, Chronic oestrogen replacement in ovariectomised rats attenuates food intake and augments c-Fos expression in the suprachiasmatic nucleus specifically during the light phase, Akira Takamata; Kayo Torii; Kana Miyake; Keiko Morimoto, 2011年10月, 106, 8, 1283, 1289, 研究論文(学術雑誌)
  • 査読あり, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, Lateral diffusion of manganese in the rat brain determined by T-1 relaxation time measured by H-1 MRI, Yoshiteru Seo; Akira Takamata; Takashi Ogino; Hironobu Morita; Masataka Murakami, In order to optimize manganese ion-enhanced MRI in thalamic and hypothalamic nuclei, we analyzed the diffusion of manganese in the brain followed by the intra-cerebroventricular application of manganese-bicine (Mn-bicine). T-1-weighted MRI intensities, with 9-pixel ROIs in the hypothalamus perpendicular to the third ventricle, were measured during continuous infusion of Mn-bicine solution in the lateral cerebroventricle. Using a relationship between the image intensity of T-1-weighted MRI and T-1 relaxation time, the image intensity was converted into the concentration of manganese. Assuming a simple diffusion process, the apparent diffusion coefficient (D-ap) of manganese (4.2 x 10(-5) mm(2) s(-1)) is much lower than that of water (6 x 10(-4) mm(2) s(-1)), and the D-ap tended to decrease when the distance from the third ventricle increased. These results suggest (1) the Mn2+ ion is trapped by neural cells during diffusion and (2) the manganese efflux is discharged from the brain via veins., 2011年05月, 61, 3, 259, 266, 研究論文(学術雑誌)
  • 査読あり, 英語, MAGNETIC RESONANCE IN MEDICINE, Mn-bicine: A Low Affinity Chelate for Manganese Ion Enhanced MRI, Yoshiteru Seo; Keitaro Satoh; Kazuto Watanabe; Hironobu Morita; Akira Takamata; Takashi Ogino; Masataka Murakami, The toxicity of free Mn(2+) is a bottleneck for the in vivo application of manganese ion enhanced MRI. To reduce free Mn(2+) concentration ([Mn(2+)]), a low affinity chelate reagent: N,N-bis(2-hydroxyethyl)glycine (bicine) was used. Considering the conditional association constant of Mn-bicine at pH 7.4 (10(2.9) M(-1)), (i) a 100 mM Mn-bicine solution should contain about 10 mM of free manganese ion, but (ii) free manganese will make up 3/4 of the final plasma concentration (0.5 mM) with an intravenous infusion of 100 mM Mn-bicine. The T(1) relaxivity of Mn-bicine in a 5 mM Mn-bicine solution was estimated as 5 mM(-1) sec(-1) at 24 degrees C, 7 T in a pH range of 6.8-7.5. Mn-bicine demonstrated a tendency for better contractility when employed with an isolated perfused frog heart, compared with MnCl(2). A venous infusion of 100 mM Mn-bicine (8.3 mu mol kg(-1) min(-1)) showed a minimal decrease and maintained a constant heart rate level and arterial pressure in rats, while rats infused with 100 mM of MnCl(2) showed a significant suppression of the hemodynamic functions. Thus, Mn-bicine appears to be a better choice for maintaining the vital conditions of experimental animals, and may improve the reproducibility of manganese ion enhanced MRI. Magn Reson Med 65:1005-1012, 2011. (C) 2010 Wiley-Liss, Inc., 2011年04月, 65, 4, 1005, 1012, 研究論文(学術雑誌)
  • 査読あり, 日本語, 繊維製品消費科学, 一般社団法人 日本繊維製品消費科学会, 重力、性周期と体液、循環、体温調節機能, 鷹股 亮; 鷹股 亮, 2011年, 52, 1, 32, 36, 研究論文(学術雑誌)
  • 査読あり, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Plasma hyperosmolality elevates the internal temperature threshold for active thermoregulatory vasodilation during heat stress in humans, Manabu Shibasaki; Ken Aoki; Keiko Morimoto; John M. Johnson; Akira Takamata, Shibasaki M, Aoki K, Morimoto K, Johnson JM, Takamata A. Plasma hyperosmolality elevates the internal temperature threshold for active thermoregulatory vasodilation during heat stress in humans. Am J Physiol Regul Integr Comp Physiol 297: R1706-R1712, 2009. First published October 7, 2009; doi:10.1152/ajpregu.00242.2009.Plasma hyperosmolality delays the response in skin blood flow to heat stress by elevating the internal temperature threshold for cutaneous vasodilation. This elevation could be because of a delayed onset of cutaneous active vasodilation and/or to persistent cutaneous active vasoconstriction. Seven healthy men were infused with either hypertonic (3% NaCl) or isotonic (0.9% NaCl) saline and passively heated by immersing their lower legs in 42 C water for 60 min (room temperature, 28 C; relative humidity, 40%). Skin blood flow was monitored via laser-Doppler flowmetry at sites pretreated with bretylium tosylate (BT) to block sympathetic vasoconstriction selectively and at adjacent control sites. Plasma osmolality was increased by similar to 13 mosmol/kgH(2)O following hypertonic saline infusion and was unchanged following isotonic saline infusion. The esophageal temperature (T(es)) threshold for cutaneous vasodilation at untreated sites was significantly elevated in the hyperosmotic state (37.73 +/- 0.11 degrees C) relative to the isosmotic state (36.63 +/- 0.12 degrees C, P < 0.001). A similar elevation of the Tes threshold for cutaneous vasodilation was observed between osmotic conditions at the BT-treated sites (37.74 +/- 0.18 vs. 36.67 +/- 0.07 degrees C, P < 0.001) as well as sweating. These results suggest that the hyperosmotically induced elevation of the internal temperature threshold for cutaneous vasodilation is due primarily to an elevation in the internal temperature threshold for the onset of active vasodilation, and not to an enhancement of vasoconstrictor activity., 2009年12月, 297, 6, R1706, R1712, 研究論文(学術雑誌)
  • 査読あり, 英語, JOURNAL OF APPLIED PHYSIOLOGY, Involvement of central angiotensin II type 1 receptors in LPS-induced systemic vasopressin release and blood pressure regulation in rats, Fumihiro Shimizu; Toshihiro Kasai; Akira Takamata, Shimizu F, Kasai T, Takamata A. Involvement of central angiotensin II type 1 receptors in LPS-induced systemic vasopressin release and blood pressure regulation in rats. J Appl Physiol 106: 1943-1948, 2009. First published April 9, 2009; doi:10.1152/japplphysiol.90516.2008.-The purpose of this study was to evaluate the involvement of central angiotensin II (ANG II) and ANG II type 1 (AT(1)) receptors in systemic release of arginine vasopressin (AVP) and blood pressure regulation during endotoxemia. LPS (150 mu g/kg) was injected intravenously 30 min after intracerebroventricular (icv) losartan (50 mu g), an AT(1) receptor antagonist, or subcutaneous (sc) captopril (50 mg/kg), an angiotensin-converting enzyme inhibitor. Rats with icv and sc saline injections served as control. LPS administration increased plasma AVP concentration from 2.1 +/- 0.2 to 15.2 +/- 2.5 pg/ml (60 min after LPS injection) without significant changes in plasma osmolality or hematocrit. LPS-induced AVP secretion was significantly attenuated by pretreatment with icv losartan (2.3 +/- 0.5 to 3.7 +/- 0.5 pg/ml) but was not attenuated after peripheral captopril treatment (2.2 +/- 0.6 to 17.6 +/- 4.2 pg/ml). LPS administration significantly decreased systolic blood pressure (SBP) by 22.7 +/- 5.4 mmHg after intravenous LPS injection in icv losartan-treated rats, while SBP remained unchanged in vehicle-treated or sc captopril-treated rats by intravenous LPS. These results indicate that central AT(1) receptors, not responsive to peripheral ANG II, play an important role in systemic AVP secretion and maintenance of blood pressure during endotoxemia., 2009年06月, 106, 6, 1943, 1948, 研究論文(学術雑誌)
  • 査読無し, その他, 臨床スポーツ医学 臨時増刊号 スポーツ栄養・食事ガイド, 運動・スポーツにおける体温調節と水分摂取, 鷹股 亮; 鷹股 亮, 2009年, 26, 60, 66
  • 査読無し, その他, 臨床スポーツ医学 臨時増刊号 スポーツ栄養・食事ガイド, 女性, 鷹股 亮; 鷹股 亮, 2009年, 26, 264, 271
  • 査読無し, 英語, LIFE SCIENCES, Mental stress induces sustained elevation of blood pressure and lipid peroxidation in postmenopausal women, Keiko Morimoto; Mayuko Morikawa; Hiroko Kimura; Nobuko Ishii; Akira Takamata; Yasuko Hara; Masami Uji; Ken-ichi Yoshida, Mental stress is thought to underlie cardiovascular events, but there is information on oxidative stress induced by mental stress in association with cardiovascular responses in women. Using a sensitive assay for plasma 4-hydroxy-2-nonenal (HNE), as a marker for oxidative stress, we addressed the relation between pressor responses and oxidative stress induced by mental or physical stress in premenopausal and postmenopausal women. Healthy subjects (7 postmenopausal and 8 premenopausal women, in early and late follicular phases) were subjected to mental and physical stress evoked by a Color Word Test (CWT) and isometric handgrip, respectively. The CWT induced a rapid elevation of diastolic blood pressure (DBP), at a higher level in the postmenopausal than in the premenopausal women (p<0.01), and this higher DBP was sustained during the CWT and recovery (p<0.01). The CWT induced a significant elevation in plasma noradrenaline in premenopausal women in the early follicular phase and in postmenopausal women (p<0.05). Plasma nitric oxide metabolites were higher in postmenopausal than in the premenopausal women in the late follicular phase (p<0.05), but did not change during exposure to the two types of stress in either group. Plasma HNE was increased during recovery from the CWT, but not the handgrip, in postmenopausal women (2.4 times, p<0.05). There was a significant difference in the time course of the CWT-induced HNE response between the postmenopausal and premenopausal women (p<0.05). These findings suggest that mental, but not physical, stress causes sustained diastolic blood pressure elevation in postmenopausal women, accompanied by heightened oxidative stress. (C) 2007 Elsevier Inc. All rights reserved., 2008年01月, 82, 1-2, 99, 107, 研究論文(学術雑誌)
  • 査読無し, 英語, Stress, Neurotransmitters, and Hormones: Neuroendocrine and Genetic Mechanisms, Effects of Estrogen on Stress-induced Activation of Peptide Neurons in PVN of Ovariectomized Rats, Yasuko Hara; Tomomi Kohno; Akira Takamata; Takashi Ueyama; Keiko Morimoto, Estrogen has been implicated in brain function related to stress responses. We investigated whether estrogen affects psychological stress-induced activation of peptide-containing or nitric oxide-producing neurons in the paraventricular hypothalamic nucleus (PVN) in ovariectomized (OVX) rats, both placebo-treated (OVX + Pla) and estrogen-treated (OVX + E2) by comparison of c-Fos expression using immunohistochemistry. Cage-switch stress increased activation in oxytocinergic neurons in the parvocellular PVN (pPVN) in OVX + Pla, but not in that of OVX + E2, rats. Moreover, the stress-induced activation in NADPH-diaphorase-positive neurons in the pPVN was larger in the OVX + E2 than in the OVX + Pla group. These findings suggest that estrogen attenuates the activation of oxytocinergic neurons in the pPVN, at least in part via nitric oxide., 2008年, 1148, 99, 105, 研究論文(学術雑誌)
  • 査読無し, 英語, STRESS, NEUROTRANSMITTERS, AND HORMONES: NEUROENDOCRINE AND GENETIC MECHANISMS, Estrogen Replacement Suppresses Pressor Response and Oxidative Stress Induced by Cage-switch Stress in Ovariectomized Rats, Keiko Morimoto; Masami Uji; Takashi Ueyama; Hiroko Kimura; Tomomi Kohno; Akira Takamata; Shigenobu Yano; Ken-Ichi Yoshida, We examined the suppressive effects of estradiol on psychological stress-induced cardiovascular responses and oxidative stress in ovariectomized rats, both placebo-treated (OVX+Pla) and estrogen-treated (OVX+E2). The elevations in blood pressure and heart rate induced by cage-switch stress were attenuated in the OVX+E2 as compared with the OVX+Pla group. N(G)-nitro-L-arginine methyl ester, administered via drinking water, reduced the difference in these responses. Furthermore, this stress increased plasma nitrotyrosine and decreased plasma nitric oxide (NO) metabolites only in the OVX+Pla group. We demonstrated that estrogen replacement suppresses cardiovascular responses to psychological stress, at least in part by improving NO bioavailability in ovariectomized rats., 2008年, 1148, 213, 218, 研究論文(学術雑誌)
  • 査読無し, 日本語, 生気象学会雑誌, Japanese Society of Biometeorology, 下肢の加温および筋肉痛を惹き起こす運動が下肢静脈コンプライアンス、毛細血管水透過係数に及ぼす影響, 鷹股 亮; 福井洋子; 山本佳奈; 鷹股亮, 立位や座位時など下肢への静水圧負荷は下肢への血液の貯留および組織への水分漏出による浮腫形成を引き起こす.下肢への血液の貯留量や組織への水分漏出量を決定する因子である静脈コンプラアンス,毛細血管水透過係数(Kf)を定量化し,これらパラメータに及ぼす局所加温および筋肉痛を惹き起こす筋運動の影響を検討した.10 名の健康な若年女性において安静臥位を 60 分間保持した後,大腿に装着したカフの圧力を 7 分ごとに 10 mmHg ずつ 50 mmHg まで上昇させ,その際の下腿の容積変化,皮膚血流量,血圧,心拍数を測定した.同様の測定を下腿加温時にも行った.1 日目の測定終了後,踵の挙上運動を 100 回,4 セット負荷して翌日筋肉痛が起こったことを確認した後 1 日目と同様の実験を行った.それぞれのカフ圧で得られた血液貯留量(下腿容積変化の第 1 相)および経毛細血管水分移動量(下腿容積変化の第 2 相)とカフ圧の関係から各々静脈コンプライアンスおよび Kf を算出した.静脈コンプライアンスは,下腿局所加温および筋肉痛を惹き起こす運動の影響を受けなかった.Kf は,筋肉痛を訴えた 2 日目に 1 日目に比べ有意に上昇した.下腿局所加温の影響は 2 日目にのみ認められ,皮膚温上昇により Kf は上昇した.以上より,筋肉痛を惹き起こす運動は Kf を上昇させ,その効果と皮膚温上昇には相互作用があることが明らかになった.
    , 2007年, 44: 13-39, 1, 13, 39
  • 査読無し, 日本語, 繊維製品消費科学, 一般社団法人 日本繊維製品消費科学会, 衣服を用いた運動時の静脈還流量維持と体温・循環反応ーその生理学的背景, 鷹股 亮; 鷹股亮, 2006年, 47, 12, 712, 718
  • 査読無し, 英語, JOURNAL OF APPLIED PHYSIOLOGY, Acute hypoosmolality attenuates the suppression of cutaneous vasodilation with increased exercise intensity, H Mitono; H Endoh; K Okazaki; T Ichinose; S Masuki; A Takamata; H Nose, We examined the hypothesis that elevation of the body core temperature threshold for forearm skin vasodilation (THFVC) with increased exercise intensity is partially caused by concomitantly increased plasma osmolality Eight young male subjects, wearing a body suit perfused with warm water to maintain the mean skin temperature at 34 +/- 1 degrees C (ranges), performed 20-min cycle-ergometer exercise at 30% peak aerobic power ((V) over dot o(2 peak)) under isoosmotic conditions (C), and at 65% (V) over dot o(2 pea)k under isoosmotic (HEXIOS) and hypoosmotic (HEXLos) conditions. In HEXLos, hypoosmolality was attained by hypotonic saline infusion with DDAVP, a V-2 agonist, before exercise. P-osmol (mosmol/kgH(2)O) increased after the start of exercise in both H-EX trials (P < 0.01) but not in C. The average P-osmol at 5 and 10 min in HEXIos was higher than in C (P < 0.01), whereas that in HEXLos was lower than in HEXIos (P < 0.01). The change in THFVC was proportional to that in P-osmol in every subject for three trials. The change in THFVC per unit change in P-osmol (Delta THFVC/Delta P-osmol, degrees C center dot mosmol(-1)center dot kgH(2)O(-1)) was 0.064 +/- 0.012 when exercise intensity increased from C to HEXIOS, similar to 0.086 +/- 0.020 when P-osmol decreased from HEXIOS to HEXLOS (P > 0.1). Moreover, there were no significant differences in plasma volume, heart rate, mean arterial pressure, and plasma lactate concentration around THFVC between HEXIOS and HEXLOS (P > 0.1). Thus the increase in THFVC due to increased exercise intensity was at least partially explained by the concomitantly increased P-osmol., 2005年09月, 99, 3, 902, 908, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Plasma hyperosmolality augments peripheral vascular response to baroreceptor unloading during heat stress, T Ito; T Itoh; T Hayano; K Yamauchi; A Takamata, The aim of this study was to elucidate the interactive effect of central hypovolemia and plasma hyperosmolality on regulation of peripheral vascular response and AVP secretion during heat stress. Seven male subjects were infused with either isotonic (0.9%; NOSM) or hypertonic (3.0%; HOSM) NaCl solution and then heated by perfusing 42 degrees C (heat stress; HT) or 34.5 degrees C water (normothermia; NT) through water perfusion suits. Sixty minutes later, subjects were exposed to progressive lower body negative pressure (LBNP) to -40 mmHg. Plasma osmolality (P-osmol) increased by similar to 11 mosmol/kgH(2)O in HOSM conditions. The increase in esophageal temperature before LBNP was much larger in HT-HOSM (0.90 +/- 0.09 degrees C) than in HT-NOSM (0.30 +/- 0.07 degrees C) (P < 0.01) because of osmotic inhibition of thermoregulation. During LBNP, mean arterial pressure was well maintained, and changes in thoracic impedance and stroke volume were similar in all conditions. Forearm vascular conductance (FVC) before application of LBNP was higher in HT than in NT conditions (P < 0.001) and was not influenced by Posmol within the thermal conditions. The reduction in FVC at -40 mmHg in HT-HOSM (-9.99 +/- 0.96 units; 58.8 +/- 4.1%) was significantly larger than in HT-NOSM (-6.02 +/- 1.23 units; 44.7 +/- 8.1%) (P < 0.05), whereas the FVC response was not different between NT-NOSM and NT-HOSM. Plasma AVP response to LBNP did not interact with P-osmol in either NT or HT conditions. These data indicate that there apparently exists an interactive effect of P-osmol and central hypovolemia on the peripheral vascular response during heat stress, or peripheral vasodilated conditions, but not in normothermia., 2005年08月, 289, 2, R432, R440, 研究論文(学術雑誌)
  • 査読無し, 英語, INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE, Effect of environmental conditions on tear dynamics in soft contact lens wearers, K Maruyama; N Yokoi; A Takamata; S Kinoshita, PURPOSE. Dry eye symptoms are often associated with soft contact lens (SCL) wear and may be affected by environmental conditions. This study was conducted to determine the effects of temperature and humidity on the tear film in SCL wearers. METHODS. All 11 enrolled subjects were males (mean age, 23.5 +/- 5.2 [SD] years), and all wore SCL daily. They were exposed in different sessions to four different conditions in an environmental chamber with the air temperature (AT) and relative humidity (RH) set at 5degreesC/10% (AT/RH), 15degreesC/20%, 25degreesC/40%, or 35degreesC/50%. Two different types of hydrogel SCL (SCL-a and SCL-b; water content 72.0% and 37.5%, respectively) were used. The meniscus tear volume was determined on a video meniscometer by measuring the tear meniscus radius (TMR) with and without SCL. The tear interference patterns on the contact lens (TIPCL) were classified into five grades (the higher the grade, the thinner the film). Using a video interferometer, the non-invasive tear film breakup time (NIBUT) was recorded with and without SCLs; ocular dryness was also scored with and without SCLs. RESULTS. Under the environmental conditions examined, there were no significant differences in the TMR without or with SCL, regardless of their type. As AT and RH decreased, there was a significant increase in the TIPCL grade (CL-a: P = 0.042; CL-b: P = 0.002), a significant decrease in NIBUT (CL-a: P = 0.004; CL-b: P = 0.001), and a significant increase in the dryness score (without SCL P = 0.023; with CL-a P = 0.009; with CL-b P = 0.003). The dryness scores were higher with CL-a than CL-b (P = 0.011 at 15degreesC/20%). Under identical experimental conditions, we observed no significant change in NIBUT in the absence of an SCL. CONCLUSIONS. AT and RH apparently had no effect on the tear volume in the presence of SCLs. As AT and RH decreased, the tear film on the SCL became thinner, NIBUT became shorter, and dryness increased. Dryness was more pronounced in eyes with SCL of the higher water content., 2004年08月, 45, 8, 2563, 2568, 研究論文(学術雑誌)
  • 査読無し, 英語, AUTONOMIC NEUROSCIENCE-BASIC & CLINICAL, Sequence of forebrain activation induced by intraventricular injection of hypertonic NaCl detected by Mn2+ contrasted T-1-weighted MRI, H Morita; T Ogino; N Fujiki; K Tanaka; TM Gotoh; Y Seo; A Takamata; S Nakamura; M Murakami, In order to define the sequence of forebrain activation involved in osmoregulation, central activation in response to intracerebroventricular injection of NaCl solution (10 mul of 0.15, 0.5, or 1.5 M) was detected using manganese-contrasted magnetic resonance imaging (MRI) in anesthetized rats. Changes in renal sympathetic nerve activity (RNA) were also measured, and the time courses of forebrain activation and RNA changes compared. NaCl injection resulted in rapid activation of the subfornical organ (SFO), organum vasculosum lamina terminalis (OVLT), and periventricular regions and the lateral hypothalamic area (LHA), then of the paraventricular hypothalamic nucleus (PVN) and supraoptic nucleus (SON). The delay in activation in the PVN and SON showed a wide variation from 0 to 5.78 min, and the average delay in the PVN (2.88 +/- 0.34 min) and SON (2.90 +/- 0.39 min) was significantly greater than that in the SFO (0.40 +/- 0.10 min) and OVLT (0.74 +/- 0.13 min). NaCl (1.5 M) injection elicited a rapid, large increase in RNA, which consisted of two components, an early rapid increase at 99 s after injection (160 +/- 27%) and a slower increase at 9 min after injection (209 +/- 34%). These results suggest that the PVN and SON are activated not only by the afferent input from the SFO and OVLT but also by diffusion of the hypertonic stimulus to these regions and probably by their intrinsic osmosensitivity. The PVN might be responsible for the second slower component of the RNA response, but cannot be responsible for the first component. (C) 2004 Elsevier B.V. All rights reserved., 2004年06月, 113, 1-2, 43, 54, 研究論文(学術雑誌)
  • 査読無し, 英語, ANESTHESIOLOGY, Effect of amino acid infusion on central thermoregulatory control in humans, Y Nakajima; A Takamata; T Matsukawa; DI Sessler; Y Kitamura; H Ueno; Y Tanaka; T Mizobe, Background. Administration of protein or amino acids enhances thermogenesis, presumably by stimulating oxidative metabolism. However, hyperthermia results even when thermoregulatory responses are intact, suggesting that amino acids also alter central thermoregulatory control. Therefore, the authors tested the hypothesis that amino acid infusion increases the thermoregulatory set point. Methods. Nine male volunteers each participated on 4 study days in randomized order: (1) intravenous amino acids infused at 4 kJ(.)kg(-1.)h(-1) for 2.5 h combined with skin-surface warming, (2) amino acid infusion combined with cutaneous cooling, (3) saline infusion combined with skin-surface warming, and (4) saline infusion combined with cutaneous cooling. Results: Amino acid infusion increased resting core temperature by 0.3 +/- 0.1 degreesC (mean +/- SD) and oxygen consumption by 18 +/- 12%. Furthermore, amino acid infusion increased the calculated core temperature threshold (triggering core temperature at a designated mean skin temperature of 34 degreesC) for active cutaneous vasodilation by 0.3 +/- 0.3 degreesC, for sweating by 0.2 +/- 0.2 degreesC, for thermoregulatory vasoconstriction by 0.3 +/- 0.3 degreesC, and for thermogenesis by 0.4 +/- 0.5 degreesC. Amino acid infusion did not alter the incremental response intensity (i.e., gain) of thermoregulatory defenses. Conclusions: Amino acid infusion increased the metabolic rate and the resting core temperature. However, amino acids also produced a synchronous increase in all major autonomic thermoregulatory defense thresholds; the increase in core temperature was identical to the set point increase, even in a cold environment with amble potential to dissipate heat. in subjects with intact thermoregulatory defenses, amino acid-induced hyperthermia seems to result from an increased set point rather than increased metabolic rate per se., 2004年03月, 100, 3, 634, 639, 研究論文(学術雑誌)
  • 査読無し, その他, 体育の科学, 運動・ホルモンと水分代謝, 鷹股 亮; 鷹股亮, 2004年, 54, 43, 47
  • 査読無し, 日本語, 日本生気象学会誌, 日本生気象学会, 水分摂取による熱中症予防 その生理学的メカニズム, 鷹股 亮; 鷹股亮, 体温調節反応,特に暑熱環境下における体温上昇に対する反応は,体液の量と組成に影響を及ぼす.発汗(温熱発汗)は体液量を減少させるだけではなく,細胞外液の浸透圧を上昇させる.これは,汗が細胞外液に比べて低張であるためである.また,皮膚血管の拡張は,特に立位時には末梢への血液の貯留を招き,静脈還流量を減少させる.細胞外液量のモニターは主に心肺圧受容器で行われているために,静脈還流量の低下は実際に体液量が変化していなくとも細胞外液(血漿)量が減少したときと同様な状態を作り出す.一方,体温上昇時の体温調節反応は,体液状態に大きく影響される.細胞外液(血漿)量の減少は,心肺圧受容器を介する反射により抑制される.また,血漿浸透圧の上昇は発汗および皮膚血管拡張反応の核心温閾値を上昇させることにより,これらの体温調節反応を抑制する.これらは,体液調節系および循環調節系が体温調節系に優先されて機能していることを示している.水分摂取により脱水の進行を予防して体液の量と浸透圧を一定に保つことにより,循環系に対する負担を軽減して体温調節機能を高いレベルで機能させることが可能になると考えられ,これが熱中症予防において水分摂取が効果的であるという事実の根拠となる.温熱脱水では,水だけではなくナトリウムを失うために水だけを摂取すると体液量は完全に回復しない.これは「自発的脱水」と呼ばれ,温熱発汗後のナトリウム摂取が不可欠であることを示す.暑熱順化や運動トレーニングにより汗ナトリウム濃度が低くなることから,有効な摂取溶液のナトリウム濃度が異なり,順化していない人ではナトリウム濃度の高い溶液の摂取が効果的となる.また,暑熱環境下で運動を行う際には,運動前にあらかじめ水分摂取を行うことが有効である.
    , 2004年, 41, 1, 55, 59
  • 査読無し, 英語, ACTA ANAESTHESIOLOGICA SCANDINAVICA, The vasoconstriction threshold is increased in obese patients during general anaesthesia, T Kasai; M Hirose; T Matsukawa; A Takamata; Y Tanaka, Background: In anaesthetized patients, body temperature decreases often, but overweight patients become less hypothermic. Obesity in itself protects body heat, and thermoregulatory reflexes may maintain normothermia in obese patients. We tested the hypothesis that even slight obesity increases the vasoconstriction threshold. Methods: Twenty male patients aged 30-65 years scheduled for open abdominal surgery were allocated to two groups: body fat greater than or equal to25% (obese group, n = 10), or <25% (normal weight group, n = 10). Anaesthesia was maintained with 0.4% isoflurane and opioid. The thermoregulatory vasoconstriction threshold was defined by the tympanic membrane temperature at which the skin temperature gradient equalled 0degreesC. Plasma adrenaline, noradrenaline and leptin were measured. Results: Age, height, heart rate and blood pressure did not differ between the two groups of patients. In the obese group the vasoconstriction threshold was higher than that in the normal weight group: 36.0 +/- 0.1 vs. 35.5 +/- 0.2degreesC. Consequently, after 4 h of anaesthesia, the core temperature was highest in the obese patients: 36.4 +/- 0.1 vs. 35.5 +/- 0.2degreesC. Conclusions: These results suggest that core temperature is maintained in obese patients because their vasoconstriction threshold to a low environmental temperature is high., 2003年05月, 47, 5, 588, 592, 研究論文(学術雑誌)
  • 査読無し, 英語, SHOCK, Reduced blood-to-tissue albumin movement after plasmapheresis, AM Stahl; CM Gillen; A Takamata; ER Nadel; GW Mack, We tested the hypothesis that a decrease in the blood-to-tissue movement of albumin contributes to the recovery of plasma albumin and plasma volume after acute plasma protein depletion (plasmapheresis). Awake and unrestrained male Sprague-Dawley rats (220-320 g) fitted with jugular catheters were plasmapheresed, and plasma volume, plasma albumin, and total plasma protein content were measured at 1, 5, 24, and 48 h postplasmapheresis. Plasma volume recovered to baseline within 1 h (4.6 +/- 0.42 vs. 4.7 +/- 0.46 mL/100 g body weight (bw), remained at baseline from 5 h to 24 h but increased to 5.5 +/- 0.57 mL/100 g bw at 48 h (P < 0.05). Plasma albumin and total protein content recovered rapidly but remained below baseline levels at 1 h (10.05 +/- 0.98 vs. 12.33 +/- 1.29 and 19.75 +/- 1.75 vs. 24.73 +/- 2.56 mg/100 g bw, respectively). Plasma protein content returned to baseline by 5 h of recovery. Tissue uptake of I-125-labeled albumin decreased in the heart, skin, skeletal muscle, and small intestines of plasmapheresed rats (P < 0.05). These data support the hypothesis that a reduction in albumin efflux from the vascular space contributes to the recovery of plasma albumin and total protein content during plasma volume recovery and eventual expansion after plasmapheresis., 2003年05月, 19, 5, 440, 447, 研究論文(学術雑誌)
  • 査読無し, 英語, ACTA ANAESTHESIOLOGICA SCANDINAVICA, Preoperative blood pressure and catecholamines related to hypothermia during general anesthesia, T Kasai; M Hirose; T Matsukawa; A Takamata; K Yaegashi; Y Tanaka, Background: We previously demonstrated that preoperative blood pressure values affect intraoperative hypothermia during general anesthesia. We hypothesized that increased catecholamine secretion could be responsible for the relationship between preoperative blood pressure and hypothermia. Methods: To evaluate the effect of preoperative systolic blood pressure (SBP) and plasma catecholamine levels on core temperature during general anesthesia, 40 male patients who were scheduled for open abdominal surgery were allocated to two groups: those whose preoperative SBP was 140 mmHg or greater (high SBP group, n = 20), and those whose SBP was less than 140 mmHg (normal SBP group, n = 20). Anesthesia was maintained with 0.4% isoflurane and opioids. Results: The average age, height, and weight of the patients in the two groups did not differ. Preoperative SBP, mean blood pressure, diastolic blood pressure and heart rate in the high SBP group were significantly higher than those in the normal SBP group. Plasma norepinephrine concentrations in the high SBP group were significantly greater than those in the normal SBP group before and 1 h after the induction of anesthesia. Tympanic membrane temperatures in the normal SBP group started to decline further just after the induction of anesthesia, more so than that in the high SBP group. The vasoconstriction threshold in the normal SBP group was significantly lower than that in the high SBP group. Conclusion: These results suggest that the higher levels of preoperative catecholamine secretion contributed to the lesser degree of intraoperative hypothermia observed in the high SBP group., 2003年02月, 47, 2, 208, 212, 研究論文(学術雑誌)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGY-LONDON, Water permeability of capillaries in the subfornical organ of rats determined by Gd-DTPA(2-) enhanced H-1 magnetic resonance imaging, Y Seo; A Takamata; T Ogino; H Morita; S Nakamura; M Murakami, The water permeability of capillaries in the subfornical organ (SFO) of rat was measured by a H-1 nuclear magnetic resonance method in combination with a venous injection of a relaxation reagent, gadolinium-diethylene triamine-N,N,N,N",N"-pentaacetic acid (Gd-DTPA(2-)), which could not pass through the blood-brain barrier (BBB). Judging from results of Gd-DTPA(2-) dose dependency in the intact brain and the BBB-permeabilized brain, Gd-DTPA(2-) could not have leaked out from the capillaries in the cortex, thalamus or SFO, but it could have been extravasated in the posterior lobe of the pituitary gland. The longitudinal (T,) relaxation time of water in the SFO region was measured by inversion-recovery magnetic resonance imaging at 4.7 T. The T-1 relaxation rates (1/T-1) before and after Gd-DTPA(2-) infusion were 0.70 +/- 0.02 s(-1) (mean +/- S.E.M., n = 9) and 1.53 +/- 0.11 s(-1) (n = 9), respectively. The rate constant for water influx to the capillaries was estimated to be 0.84 +/- 0.11 s(-1) (n = 9) which corresponds with a diffusive membrane permeability (P-d) of 3.7 x 10(-3) cm s(-1). Compared with values found in the literature available on this subject, this Pd value for the capillaries in the SFO was the same order of magnitude as that for transmembrane permeability of water for the vasa recta, and it may be 10-100 times larger than that of the blood-brain barrier in the cortex. Areas of the cortex and thalamus showed minimal changes in the T-1 relaxation rate (ca 0.09 s(-1)), but these values were not statistically significant and they corresponded to P-d values much smaller than those found in the SFO. From these results, we conclude that the capillaries in the SFO have one of the highest water permeability values among all of the capillaries in the brain. It is also suggested that this magnetic resonance imaging, based on T-1 relaxation rate, is a useful method to detect local water permeability in situ., 2002年11月, 545, 1, 217, 228, 研究論文(学術雑誌)
  • 査読無し, 英語, ANESTHESIA AND ANALGESIA, Preoperative risk factors of intraoperative hypothermia in major surgery under general anesthesia, T Kasai; M Hirose; K Yaegashi; T Matsukawa; A Takamata; Y Tanaka, Preoperative factors, such as age and body habitus, affect intraoperative hypothermia during general anesthesia. In a preliminary study, we developed a logistic model to retrospectively evaluate predictors of intraoperative hypothermia in patients who received major surgery. The following factors were selected to develop the model: Z = -15.014 + 0.097 x (Age) + 0.263 x (Height) - 0.323 x (Weight) - 0.055 x (Preoperative systolic blood pressure) - 0.121 X (Preoperative heart rate). By using this model, the probability of hypothermia can be estimated by applying the following formula: Probability = 1/(1 + e(-z)). If an estimated probability of hypothermia was >0.5, the sensibility of prediction was 81.5% and the specificity was 83%. In the second study, the model was applied prospectively to other patients, and the validity of the logistic model was evaluated. The core temperature showed a significant decrease in patients with a probability >0.7, who were predicted to be hypothermic, and their thermoregulatory vasoconstriction threshold also showed a significant decrease, compared with the patients with a probability less than or equal to0.3, who were predicted to be normothermic. We concluded that intraoperative hypothermia could be predicted from preoperative characteristics such as age, height, weight, systolic blood pressure, and heart rate., 2002年11月, 95, 5, 1381, 1383, 研究論文(学術雑誌)
  • 査読無し, 英語, NEUROSCIENCE LETTERS, Detection of hypothalamic activation by manganese ion contrasted T-1-weighted magnetic resonance imaging in rats, H Morita; T Ogino; Y Seo; N Fujiki; K Tanaka; A Takamata; S Nakamura; M Murakami, To examine the usefulness of Mn2+ contrasted magnetic resonance imaging (MRI) in hypothalamic imaging, images obtained using T-1-weighted MRI were compared with Fos expression, which is known to increase after activation of voltage-dependent Ca2+ channels. Intravenous infusion of MnCl2 elicited a rapid increase in the T-1-weighted MRI signal intensity in the vessels and ventricles, but not in the brain parenchyma, suggesting that Mn2+ did not diffuse freely across the blood-brain barrier. When the blood-brain barrier was broken by right intracarotid arterial injection of 25% D-mannitol, an increased signal intensity was seen in the right brain. Intracarotid arterial injection of hypertonic NaCl elicited rapid and striking increases in signal intensity in the paraventricular hypothalamic nucleus, supraoptic nucleus, and preoptic area, which are thought to be involved in central osmotic regulation. These observations were consistent with the Fos expression results. These results indicate that Mn2+ contrasted MRI is a useful technique for investigating the autonomic center in the hypothalamus. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved., 2002年06月, 326, 2, 101, 104, 研究論文(学術雑誌)
  • 査読無し, 英語, ANESTHESIA AND ANALGESIA, Upright posture reduces thermogenesis and augments core hypothermia, Y Nakajima; A Takamata; T Ito; DI Sessler; Y Kitamura; G Shimosato; S Taniguchi; H Matsuyama; Y Tanaka; T Mizobe, We recently reported that baroreceptor-mediated reflexes modulate thermoregulatory vasoconstriction during lower abdominal surgery. Accordingly, we examined the hypothesis that postural differences and the related alterations in baroreceptor loading similarly modulate the thermogenic (i.e., shivering) response to hypothermia in humans. In healthy humans (n = 7), cold saline was infused W (30 mL/kg at 4degreesC) for 30 min to decrease core temperature. Each participant was studied on 2 separate days, once lying supine and once sitting uptight. Tympanic membrane temperature and oxygen consumption were monitored for 40 min after each saline infusion. The decrease in core temperature upon completion of the infusion in the upright posture position was 1.24degreesC +/- 0.07degreesC, which was significantly greater than the 1.02degreesC +/- 0.06degreesC seen in the supine position. The core temperature was reduced by 0.59degreesC +/- 0.07degreesC in the upright position but only by 0.37degreesC +/- 0.05degreesC in the supine position when the increase in oxygen consumption signaling thermogenic shivering occurred. Thus, the threshold temperature for thermogenesis was significantly less in the upright than the supine position. The gain of the thermogenic response did not differ significantly between the positions (363 +/- 69 mL.min(-1).degreesC(-1) for upright and 480 +/- 80 mL . min(-1) . degreesC(-1) for supine). The skin temperature gradient was significantly larger in the upright than in the supine posture, suggesting that the peripheral vasoconstriction was augmented by upright posture. Plasma norepinephrine concentrations increased in response to cold saline infusion under both conditions, but the increase was significantly larger in the upright than in the supine posture. Baroreceptor unloading thus augments the peripheral vasoconstrictor and catecholamine response to core hypothermia but simultaneously reduces thermogenesis, which consequently aggravated the core temperature decrease in the upright posture., 2002年06月, 94, 6, 1646, 1651, 研究論文(学術雑誌)
  • 査読無し, その他, 綜合臨床, 夏期の作業・運動時における効果的な水分補給, 鷹股 亮, 2002年, 51, 2295, 2296
  • 査読無し, 英語, JAPANESE JOURNAL OF PHYSIOLOGY, Role of blood volume in the age-associated decline in peak oxygen uptake in humans, T Ito; A Takamata; K Yaegashi; T Itoh; T Yoshida; T Kawabata; M Kimura; T Morimoto, It has been reported that maximal oxygen uptake ((V) over dot O-2max) is linearly correlated with blood volume (BV) in young people and that there is a reduction in (V) over dot O-2max with aging. To examine the involvement of BV in the reduction of (V) over dot O-2max, we used an incremental cycle ergometer protocol in a semirecumbent position to determine the relationship between peak oxygen uptake ((V) over dot O-2peak) and BV in older subjects (69.1 +/- 1.0 years, n=22), then compared that relationship with that in young subjects (22.3 +/- 0.5 years; n=31). In the present study, (V) over dot O-2peak and BV were significantly lower in the older subjects, compared with those in the young subjects. A linear correlation was demonstrated between the (V) over dot O-2peak and BV in both the older (r=0.705; p<0.001) and the young (r=0.681; p<0.001) subjects within the groups. However, an analysis of covariance with BV as a covariate revealed that (V) over dot O-2peak at a given BV was smaller in the older subjects than in the young subjects (p<0.001), i.e., graphically, the regression line determined for the older subjects showed a downward shift. The decreased peak heart rate as a result of aging (153 +/- 3 beats/min in the older vs. 189 +/- 2 beats/min in the young subjects) contributed partly to this downward shift. These results suggest that the BV is an important determinant factor for (V) over dot O-2peak, especially within an age group, and that the age-associated decline of (V) over dot O-2peak is also, to a relatively larger degree, because of factors other than BV and heart rate., 2001年10月, 51, 5, 607, 612, 研究論文(学術雑誌)
  • 査読無し, 英語, JAPANESE JOURNAL OF PHYSIOLOGY, Effects of pCO(2) on the CSF turnover rate in rats monitored by Gd-DTPA enhanced T-1-weighted magnetic resonance imaging, A Takamata; Y Seo; T Ogino; K Tanaka; N Fujiki; H Morita; M Murakami, The cerebrospinal fluid (CSF) secretion of rat was monitored by longitudinal relaxation time-weighted magnetic resonance imaging (T-1-weighted MRI) in combination with a ventricular injection of a T-1-relaxation reagent: gadolinium-diethylene triamine-N,N,N',N",N"-pentaacetic acid (Gd-DTPA). A cannula was inserted in the left lateral ventricle, and 5 mul of 8.5 mm Gd-DTPA was injected as a CSF marker. Changes in the image intensity of the CSF were measured every 30 s, and the turnover rate of CSF (k) in the left lateral ventricle was obtained from the dilution of Gd-DTPA, based on the assumption of a single compartment model. In the control conditions, k was 0.158 +/- 0.009 min(-1) at an arterial blood CO2 tension (pCO(2)) of 38.6 +/- 2.2 mmHg (n=10), which corresponds to the CSF secretion rate of 3.6 mul min(-1). The k value was decreased (0.078 +/- 0.010 min(-1), n=4) by a carbonic-anhydrase inhibitor (acetazolamide). The turnover rate was decreased by hypocapnia (0.094+/-0.019 min(-1), pCO(2)=24.7 +/- 2.9 mmHg, n=4), and it increased gradually and reached a plateau level as a result of hypercapnia (0.194 +/- 0.011 min(-1), pCO(2)=104.5 +/- 7.1 mmHg, n=10). These results suggested that CO2 upregulates the secretion of CSF in the rat., 2001年10月, 51, 5, 555, 562, 研究論文(学術雑誌)
  • 査読無し, 英語, ACTA ANAESTHESIOLOGICA SCANDINAVICA, Preoperative blood pressure and intraoperative hypothermia during lower abdominal surgery, T Kasai; M Hirose; T Matsukawa; A Takamata; M Kimura; Y Tanaka, Background: Preoperative factors including age and body habitus affect intraoperative hypothermia during general anesthesia. We hypothesized that preoperative blood pressure also plays a contributory role in the induction of intraoperative hypothermia. Methods: We evaluated the effect of preoperative systolic blood pressure (SBP) on core temperature during lower abdominal surgery under general anesthesia. In 36 female patients under 65 years of age, patients with a preoperative SBP of 140 mmHg or greater upon arrival in the operating theater were assigned to the high SBP group (n=18), while those with SBP below 140 mmHg were assigned to the normal SBP group (n=18). Anesthesia was maintained with isoflurane and nitrous oxide combined with epidural buprenorphine, and routine thermal care was provided intraoperatively. Results: There were no significant differences in age, height or weight between the two groups. Tympanic membrane temperature in the normal SBP group started to decrease significantly from 15 min after induction of anesthesia compared to that in the high SBP group, and continued to decrease further at two hours after induction. Vasoconstriction threshold, determined to be tympanic membrane temperature at the time when a forearm minus finger skin surface gradient exceeded 0 degreesC, was significantly higher in the high SBP group than in the normal SBP group. Conclusion: These results suggest that preoperative SBP has some preventive effect on the decrease in intraoperative core temperature during lower abdominal surgery under general anesthesia., 2001年09月, 45, 8, 1028, 1031, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Relationship of osmotic inhibition in thermoregulatory responses and sweat sodium concentration in humans, A Takamata; T Yoshida; N Nishida; T Morimoto, Heat acclimatization improves thermoregulatory responses to heat stress and decreases sweat sodium concentration ([Na+](sweat)). The reduced [Na+](sweat) results in a larger increase in plasma osmolality (P-osmol) at a given amount of sweat output. The increase in Posmol inhibits thermoregulatory responses to increased body core temperature. Therefore, we hypothesized that the inhibitory effect of plasma hyperosmolality on the thermoregulatory responses to heat stress should be attenuated with the reduction of [Na+](sweat) due to heat acclimatization. Eleven subjects (9 male and 2 female) were passively heated by immersing their lower legs into water at 42 degreesC (room temperature 28 degreesC and relative humidity 30%) for 50 min following isotonic or hypertonic saline infusion. We determined the increase in the esophageal temperature (T-es) required to elicit sweating and cutaneous vasodilation (CVD) (DeltaT(es) thresholds for sweating and CVD, respectively) in each condition and calculated the elevation of the T-es thresholds per unit increase in P-osmol as the osmotic inhibition of sweating and CVD. The osmotic shift in the DeltaT(es) thresholds for both sweating and CVD correlated linearly with [Na+](sweat) (r = 0.858 and r = 0.628, respectively). Thus subjects with a lower [Na+](sweat) showed a smaller osmotic elevation of the DeltaT(es) thresholds for sweating and CVD. These results suggest the possibility that heat acclimatization attenuates osmotic inhibition of thermoregulatory responses as well as reducing [Na+](sweat)., 2001年03月, 280, 3, R623, R629, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Baroreflex modulation of peripheral vasoconstriction during progressive hypothermia in anesthetized humans, Y Nakajima; T Mizobe; A Takamata; Y Tanaka, Mild hypothermia is a major concomitant of surgery under general anesthesia. We examined the hypothesis that baroreceptor loading/unloading modifies thermoregulatory peripheral vasoconstriction and, consequently, body core temperature in subjects undergoing lower abdominal surgery with general anesthesia. Thirty-six patients were divided into four groups: control group (C), applied positive end-expiratory pressure (PEEP; 10 cmH(2)O) group (P), applied leg-up position group (L), and a group of leg-up position patients with PEEP starting 90 min after induction of anesthesia (L + P). The esophageal temperature (T-es) and the forearm-fingertip temperature gradient, as an index of peripheral vasoconstriction, were monitored for 3 h after induction of anesthesia. Mean arterial pressure and pulse pressure did not change during the study in any group. The change in right atrial transmural pressure from the baseline value was 0.3 +/- 0.1 mmHg in C, -3.0 +/- 0.5 mmHg in P, and 2.3 +/- 0.4 mmHg in L (P < 0.01). The change in Tes at the end of the study was -1.7 +/- 0.1 (35.1 +/- 0.1)degrees C in C, -1.1 +/- 0.1 (35.7 +/- 0.1)degrees C in P, and -2.7 +/- 0.1 (34.1 +/- 0.1)degrees C in L, showing significant differences (P < 0.01). The Tes threshold for thermal peripheral vasoconstriction was 35.6 +/- 0.1 degrees C in C, 36.2 +/- 0.2 degrees C in P, and 34.8 +/- 0.2 degrees C in L (P, 0.01). Excessive Tes decrease in the leg-up-position operation was attenuated by applying PEEP (L + P group; P < 0.05). Our data indicate that baroreceptor loading augments and unloading prevents perioperative hypothermia in anesthetized and paralyzed subjects by reducing and increasing the body temperature threshold for peripheral vasoconstriction, respectively., 2000年10月, 279, 4, R1430, R1436, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Effect of acute hypoxia on vasopressin release and intravascular fluid during dynamic exercise in humans, A Takamata; H Nose; T Kinoshita; M Hirose; T Itoh; T Morimoto, To test the hypothesis that acute hypoxia does not modify the relationship between plasma vasopressin concentration ([AVP](p)) and plasma osmolality (P-osmol) during exercise and that the increase in [AVP](p) during exercise is due mainly to the exercise intensity-dependent increase in P-osmol, we examined [AVP](p) during a graded exercise in a hypoxic condition (13% O-2, N-2 balance) in seven healthy male subjects. A graded exercise in a normoxic condition on a separate day served as the control. Hypoxia reduced peak aerobic power ((V) over dotO(2 peak)) by 32.4 +/- 2.7%. Blood samples obtained during rest and at around 25, 45, 65, 80, and 100% of (V) over dotO(2) (peak) of each of the respective conditions were used for analyses of intravascular water and electrolyte balance. The pattern of the changes in fluid and electrolyte balance in response to percent (V) over dotO(2 peak) was similar between the two conditions. Plasma volume decreased linearly as percent (V) over dotO(2 peak) increased while P-osmol increased in a curvilinear fashion with a steep increase occurring at above similar to 66% (V) over dotO(2 peak). Above this relative exercise intensity, plasma sodium, potassium, and lactate concentrations also increased, whereas plasma bicarbonate concentration decreased. Thus transvascular fluid movement at above similar to 66% (V) over dotO(2 peak) was due to the net efflux of hypotonic fluid out of the vascular space in both conditions. The relationship between [AVP](p) and P-osmol during exercise in response to relative exercise intensity was similar between the two conditions. The results indicate that acute mild hypoxia itself has no direct effect on vasopressin release, and it does not modify the relationship between [AVP](p) and P-osmol during exercise. The results also support the hypothesis that exercise-induced vasopressin release is primarily stimulated by increased P-osmol produced by hypotonic fluid movement out of the vascular space in a relative exercise intensity-dependent manner., 2000年07月, 279, 1, R161, R168, 研究論文(学術雑誌)
  • 日本語, 体力科学, (一社)日本体力医学会, サッカー選手の夏季合宿中における水分代謝の変化, 伊藤 倫之; 鷹股 亮; 武田 ひとみ; 河端 隆志, 2000年06月, 49, 3, 441, 441
  • 査読無し, 英語, BRAIN RESEARCH, LPS-induced Fos expression in oxytocin and vasopressin neurons of the rat hypothalamus, W Matsunaga; S Miyata; A Takamata; H Bun; T Nakashima; T Kiyohara, The aim of this study was to examine the involvement of the hypothalamic oxytocin (OXT) and vasopressin (AVP) neurons in acute phase reaction using quantitative dual-labeled immunostaining with Fos and either OXT and AVP in several hypothalamic regions. Administration of low dose (5 mu g/kg) and high dose (125 mu g/kg) of LPS induced intense nuclear Fos immunoreactivity in many OXT and AVP neurons in all the observed hypothalamic regions. The percentage of Fos-positive nuclei in OXT magnocellular neurons was higher than that of AVP magnocellular neurons in the supraoptic nucleus (SON), the magnocellular neurons in the paraventricular nucleus (magPVN), rostral SON (rSON), and nucleus circularis (NC), whose axons terminate at the posterior pituitary for peripheral release. The percentage of Fos-positive nuclei in AVP parvocellular neurons in the paraventricular nucleus (parPVN) was higher than that of OXT parvocellular neurons, whose axons terminate within the brain for central release. Moreover, the percentage of Fos-positive nuclei in AVP magnocellular neurons of the SON and rSON was significantly higher than that of the magPVN and NC when animals were given LPS via intraperitoneal (i.p.)-injection. This regional heterogeneity was not observed in OXT magnocellular neurons of i.p.-injected rats or in either OXT or AVP magnocellular neurons of intravenous (i.v.)-injected rats. The present data suggest that LPS-induced peripheral release of AVP and OXT is due to the activation of the magnocellular neurons in the SON, magPVN, NC, and rSON, and the central release of those hormones is in part derived from the activation of parvocellular neurons in the PVN. It is also suggested that the activation of AVP magnocellular neurons is heterogeneous among the four hypothalamic regions, but that of OXT magnocellular neurons is homogenous among these brain regions in response to LPS administration. (C) 2000 Elsevier Science B.V. All rights reserved., 2000年03月, 858, 1, 9, 18, 研究論文(学術雑誌)
  • 査読無し, その他, 保健の科学, スポーツと水分摂取, 鷹股 亮; 鷹股亮, 2000年, 42, 332, 339
  • 査読無し, その他, FOOD Style 21, 運動時の水分補給とスポーツ飲料, 鷹股 亮, 2000年, 6, 62, 66
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Effect of an exercise-heat acclimation program on body fluid regulatory responses to dehydration in older men, A Takamata; T Ito; K Yaegashi; H Takamiya; Y Maegawa; T Itoh; JE Greenleaf; T Morimoto, We examined if an exercise-heat acclimation program improves body fluid regulatory function in older subjects, as has been reported in younger subjects. Nine older (Old; 70 +/- 3 yr) and six younger (Young; 25 +/- 3 yr) male subjects participated in the study. Body fluid regulatory responses to an acute thermal dehydration challenge were examined before and after the B-day acclimation session. Acute dehydration was produced by intermittent light exercise [4 bouts of 20-min exercise at 40% peak rate of oxygen consumption (VO2peak) Separated by 10 min rest] in the heat (36 degrees C; 40% relative humidity) followed by 30 min of recovery without fluid intake at 25 degrees C. During the 2-h rehydration period the subjects drank a carbohydrate-electrolyte solution ad libitum. In the preacclimation test, the Old lost similar to 0.8 kg during dehydration and recovered 31 +/- 4% of that loss during rehydration, whereas the Young lost similar to 1.2 kg and recovered 56 +/- 8% (P < 0.05, Young vs. Old). During the B-day heat acclimation period all subjects performed the same exercise-heat exposure as in the dehydration period. Exercise-heat acclimation increased plasma volume by similar to 5% (P < 0.05) in Young subjects but not in Old. The body fluid loss during dehydration in the postacclimation test was similar to that in the preacclimation in Young and Old. The fractional recovery of lost fluid volume during rehydration increased in Young (by 80 +/- 9%; P < 0.05) but not in Old (by only 34 +/- 5%; NS). The improved recovery from dehydration in Young was mainly due to increased fluid intake with a small increase in the fluid retention fraction. The greater involuntary dehydration (greater fluid deficit) in Old was accompanied by reduced plasma vasopressin and aldosterone concentrations, renin activity, and subjective thirst rating (P < 0.05,Young vs. Old). Thus older people have reduced ability to facilitate body fluid regulatory function by exercise-heat acclimation, which might be involved in attenuation of the acclimation-induced increase in body fluid volume., 1999年10月, 277, 4, R1041, R1050, 研究論文(学術雑誌)
  • 査読無し, 英語, JAPANESE JOURNAL OF PHYSIOLOGY, Comparison between tail skin blood flow measurements by ultrasonic Doppler flowmetry and plethysmography during heating in anesthetized rats, Y Nakajima; H Nose; A Takamata, Tail skin blood flow (TBFu) was directly measured in anesthetized and passively heated rats by ultrasonic Doppler flowmetry during heating, and the values were compared to those (TBFp) simultaneously measured by venous-occlusion plethysmography. TBFp was estimated from the values per unit tissue multiplied by the tail volume, the shape of which was assumed to be a cone. TBFp was highly correlated with TBFu, with a regression equation of TBFp=0.7TBF(u)+0.1 (r(2)=0.94, p<0.001). Although TBFp was slightly lower than TBFu, the equation is useful to estimate the absolute values of tail skin blood flow from the values of plethysmography in awake rats., 1999年02月, 49, 1, 121, 124, 研究論文(学術雑誌)
  • 日本語, 日本生理学雑誌, (一社)日本生理学会, パルス式色素希釈法による循環血液量測定の評価:Evans Blueによる測定との比較, 八重樫 和宏; 伊藤 倫之; 鷹股 亮; 河端 隆志; 森本 武利, 1999年01月, 61, 1, 56, 57
  • 日本語, 体力科学, (一社)日本体力医学会, 最大酸素摂取量と血液量の関係に対する年齢の影響, 伊藤 倫之; 鷹股 亮; 木村 みさか; 河端 隆志; 芳田 哲也; 森本 武利, 1998年12月, 47, 6, 834, 834
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Plasma hyperosmolality and arterial pressure regulation during heating in dehydrated and awake rats, Y Nakajima; H Nose; A Takamata, To gain better insights into the effect of dehydration on thermal and cardiovascular regulation during hyperthermia, we examined these regulatory responses during body heating in rats under isosmotic hypovolemia and hyperosmotic hypovolemia. Rats were divided into four groups: normovolemic and isosmotic (C), hypovolemic and isosmotic [L, plasma volume loss (Delta PV) = -20% of control], hypovolemic and less hyperosmotic [HL1, increase in plasma osmolality (Delta P-osm) = 23 mosmol/kgH(2)O, Delta PV = -16%], and hypovolemic and more hyperosmotic (HL2, Delta P-osm = 52 mosmol/kgH(2)O, Delta PV = -17%). Hyperosmolality was attained by subcutaneous injection of hypertonic saline and hypovolemia by intra-arterial injection of furosemide before heating, Then rats were placed in a thermocontrolled box (35 degrees C air temperature, similar to 20% relative humidity) for 1-2 h until rectal temperatures (T-re) reached 40.0 degrees C. Mean arterial pressure in L decreased with rise in T-re (P < 0.001), whereas mean arterial pressure remained constant in the other groups. Maximal tail skin blood flow in L, HL1, and HL2 was decreased to similar to 30% of that in C (P < 0.001). T-re threshold for tail skin vasodilation (TVD) was not changed in L, whereas the threshold shifted higher in the HL groups. T-re threshold for TVD was highly correlated with P-osm (r = 0.94, P < 0.001). Heart rate in the HL groups increased with rise in T-re (P < 0.001), whereas it remained unchanged in C and L. Cardiovascular responses to heating were not influenced by V-1 antagonist in C, L, and HL2. Thus isotonic hypovolemia attenuates maximal tail skin blood flow, whereas hypertonic hypovolemia causes an upward shift of T-re threshold for TVD and an increase in heart rate during hyperthermia. These results suggest that plasma hyperosmolality stimulates presser responses in the hypovolemic condition that subsequently contribute to arterial pressure regulation during heat stress., 1998年11月, 275, 5, R1703, R1711, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Role of plasma osmolality in the delayed onset of thermal cutaneous vasodilation during exercise in humans, A Takamata; K Nagashima; H Nose; T Morimoto, To elucidate the role of increased plasma osmolality (P-osmol), which occurs during exercise in the regulation of cutaneous vasodilation (CVD) during exercise, we determined the relationship between the change in esophageal temperature (Delta T-es) required to elicit CVD (Delta T-es threshold for CVD) and P-osmol during light and moderate exercise (30 and 55% of peak oxygen consumption, respectively) and passive body heating. Then we compared the relationship with the data obtained in our previous study [A. Takamata, K. Nagashima, H. Nose, and T. Morimoto.Am. J. Physiol. 273 (Regulatory Integrative Comp. Physiol. 42): R197-R204, 1997], in which we determined the relationships during passive body heating following isotonic (0.9% NaCl) or hypertonic (2 or 3% NaCl) saline infusions in the same subjects. P-osmol values at 5 min after the onset of exercise were 287.5 +/- 0.9 mosmol/kgH(2)O during light exercise and 293.0 +/- 1.2 mosmol/kgH(2)O during moderate exercise. P-osmol just before passive body heating was 289.9 +/- 1.4 mosmol/kgH(2)O. The Delta T-es threshold for CVD was 0.09 +/- 0.05 degrees C during light exercise, 0.31 +/- 0.09 degrees C during moderate exercise, and 0.10 +/- 0.05 degrees C during passive body heating. The relationship between the Delta T-es threshold for CVD and P-osmol was shown to be on the same regression line both during exercise and during passive body heating with or without infusions [A. Takamata, K. Nagashima, H. Nose, and T. Morimoto. Am. J. Physiol. 273 (Regulatory Integrative Comp. Physiol. 42): R197-R204, 1997]. Our data suggest that the elevated body core temperature threshold for CVD during exercise could be the result of increased P-osmol induced by exercise and is not due to reduced plasma volume or the intensity of the exercise itself., 1998年07月, 275, 1, R286, R290, 研究論文(学術雑誌)
  • 査読無し, 英語, JOURNAL OF APPLIED PHYSIOLOGY, Effect of continuous negative-pressure breathing on skin blood flow during exercise in a hot environment, K Nagashima; H Nose; A Takamata; T Morimoto, To assess the impact of continuous negative-pressure breathing (CNPB) on the regulation of skin blood flow, we measured forearm blood flow (FBF) by venous-occlusion plethysmography and laser-Doppler flow (LDF) at the anterior chest during exercise in a hot environment (ambient temperature = 30 degrees C, relative humidity = similar to 30%). Seven male subjects exercised in the upright position at an intensity of 60% peak oxygen consumption rate for 40 min with and without CNPB after 20 min of exercise. The esophageal temperature (T-es) in both conditions increased to 38.1 degrees C by the end of exercise, without any significant differences between the two trials. Mean arterial pressure (MAP) increased by similar to 15 mmHg by 8 min of exercise, without any significant difference between the two trials before CNPB. However, CNPB reduced MAP by similar to 10 mmHg after 24 min of exercise (P < 0.05). The increase in FBF and LDF in the control condition leveled off after 18 min of exercise above a T-es of 37.7 degrees C, whereas in the CNPB trial the increase continued, with a rise in T-es despite the decrease in MAP. These results suggest that CNPB enhances vasodilation of skin above a T-es of similar to 38 degrees C by stretching intrathoracic baroreceptors such as cardiopulmonary baroreceptors., 1998年06月, 84, 6, 1845, 1851, 研究論文(学術雑誌)
  • 査読無し, 英語, BRAIN FUNCTION IN HOT ENVIRONMENT, Thermoregulation and body fluid in hot environment, T Morimoto; T Itoh; A Takamata, 1998年, 115, 499, 508
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Osmoregulatory inhibition of thermally induced cutaneous vasodilation in passively heated humans, A Takamata; K Nagashima; H Nose; T Morimoto, We examined the effect of increased plasma osmolality (P-osm) on cutaneous vasodilatory response to increased esophageal temperature (T-es) in passively heated human subjects (n = 6). To modify P-osm, subjects were infused with 0.9, 2, or 3% NaCl infusions (Inf) for 90 min on separate days. Infusion rates were 0.2, 0.15, and 0.125 ml . min(-1). kg body wt(-1) for 0.9, 2, and 3% Inf, respectively, which produced relatively similar plasma volume expansion. Thirty minutes after the end of infusion, subjects immersed their lower legs in a water bath at 42 degrees C (room temperature 28 degrees C) for 60 min after 10 min of preheating control measurements. Passive heating without infusion (NI) served as time control to account for the effect of volume expansion. P-osm (mosmol/kgH(2)O) values at the onset of passive heating were 289.9 +/- 1.4, 292.1 +/- 0.6, 298.7 +/- 0.7, and 305.6 +/- 0.6 after NI, 0.9% Inf, 2% Inf, and 3% Inf, respectively. The increases in T-es (Delta T-es) at equilibrium during passive heating (mean Delta T-es during 55-60 min) were 0.47 +/- 0.08, 0.59 +/- 0.08, 0.85 +/- 0.13, and 1.09 +/- 0.12 degrees C after NI, 0.9% Inf, 2% Inf, and 3% Inf, respectively, which indicates that T-es at equilibrium increased linearly as P-osm increased. Delta T-es required to elicit cutaneous vasodilation (Delta T-es threshold for cutaneous vasodilation) also increased linearly as P-osm increased as well as the Delta T-es threshold for sweating. The calculated increases in these thresholds per unit rise in P-osm from regression analysis were 0.044 degrees C for the cutaneous vasodilation and 0.034 degrees C for sweating. Thus the Delta T-es thresholds for cutaneous vasodilation and sweating are shifted to higher Delta T-es along with the increase in P-osm, and these shifts resulted in the higher increase in T-es during passive heating., 1997年07月, 273, 1, R197, R204, 研究論文(学術雑誌)
  • 査読無し, 英語, Int J Biometeorol., Integrative regulations of body temperature and body fluid in humans exercising in a hot environment.(共著)&0d0a;, 鷹股 亮; Nose H; Takamata A, 1997年02月, 40, 1, 42, 49, 研究論文(学術雑誌)
  • 査読無し, 英語, THERMOREGULATION, Negative pressure breathing and the control of skin blood flow during exercise in a hot environment, K Nagashima; T Yoshida; H Nose; A Takamata; T Morimoto, 1997年, 813, 604, 609, 研究論文(学術雑誌)
  • 査読無し, その他, Space Utilization Research., 静脈還流量からみた微少重力下での筋血流調節, 鷹股 亮; 能勢博; 上条義一郎; 竹野欽昭; 柳平担徳; 酒井秋男; 永島計; 鷹股亮; 森本武利, 1997年, 14, 18, 21
  • 査読無し, その他, 臨床スポーツ医学, 運動時の体液調節, 鷹股 亮, 1997年, 14, 721, 727
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, Thirst and fluid regulatory responses to hypertonicity in older adults, NS Stachenfeld; GW Mack; A Takamata; L DiPietro; ER Nadel, To assess the fluid regulatory responses in aging adults, we measured thirst perception and renal osmoregulation during and after infusion of hypertonic (3% NaCl) saline in older (72 +/- 2 yr, n = 6) and younger (26 +/- 2 yr, n = 6) subjects. Hypertonic saline was infused at 0.1 ml . min(-1). kg(-1) for 120 min. On a separate day, the same subjects were infused identically with isotonic saline as a control. After infusion and a 30-min equilibration period, the subjects drank water ad libitum for 180 min. Hypertonic saline infusion Zed to graded increases in plasma osmolality (P-osm; 18 +/- 2 and 20 +/- 2 mosmol/kgH(2)O) and percent changes in plasma volume (16.2 +/- 1.9 and 18.0 +/- 1.2%) that were similar in older and younger subjects. Osmotically stimulated increases in thirst (94.8 +/- 18.9 and 88.3 +/- 25.6 mm), assessed on a line rating scale, and plasma arginine vasopressin concentration (6.08 +/- 1.50 and 4.51 +/- 1.37 pg/ml, for older and younger, respectively) were also unaffected by age. Despite subsequent hypervolemia, both groups of subjects drank sufficient water to restore preinfusion levels of P-osm. Renal handling of free water and sodium was also unaffected by age during recovery from hypertonic saline infusion, but was significantly lower in older subjects during recovery from isotonic saline infusion, resulting in net fluid retention and a significant fall in P-osm (6 mosmol/kgH(2)O). In contrast to earlier reports of a blunted thirst response to dehydration and hypertonicity, we found that osmotically stimulated thirst and renal osmoregulation were intact in older adults after hypertonic saline infusion., 1996年09月, 271, 3, R757, R765, 研究論文(学術雑誌)
  • 査読無し, その他, 日常診療と血液, スポーツが血中イオンに及ぼす影響と循環血液量の変化について, 鷹股 亮, 1996年, 6, 403, 409
  • 査読無し, その他, 臨床スポーツ医学, 運動時の体温調節と水分摂取., 鷹股 亮, 1996年, 13, 68, 73
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, BODY-TEMPERATURE MODIFICATION OF OSMOTICALLY INDUCED VASOPRESSIN SECRETION AND THIRST IN HUMANS, A TAKAMATA; GW MACK; NS STACHENFELD; ER NADEL, We examined the effect of increased body core temperature (T-es) on the plasma arginine vasopressin concentration ([AVP](p)) and thirst responses to increased plasma osmolality (P-osm) induced by 3% NaCl infusion for 120 min in seven healthy humans. T-es was increased by immersion of the lower legs in 41 degrees C water in a 28 degrees C room (passive heating; HT). Immersion of the lower legs in 34.5 degrees C water on a separate day served as the control (thermoneutral; NT). The 120-min hypertonic saline infusion was initiated 30 min after the onset of leg immersion and was followed by a 30-min rehydration period. T-es in HT increased by 0.21 +/- 0.04 degrees C before infusion and by 0.86 +/- 0.08 degrees C at the end of infusion. The change in T-es in NT before and after the infusion was negligible. P-osm was increased by 15.0 +/- 1.0 mosmol/kgH(2)O by infusion in both NT and HT. [AVP](p) increased by 3.48 +/- 0.72 pg/ml in NT and by 7.59 +/- 1.02 pg/ml in HT. Thus the increase in [AVP](p) at a given increase in P-osm was markedly higher in HT than in NT. The plasma renin activity response to hypertonic saline infusion in both conditions was similar. Subjective thirst rating and cumulative water intake during rehydration were higher in HT than in NT. The calculated increase in [AVP](p) per unit rise in T-es at a P-osm of 299 +/- 1 mosmol/kgH(2)O was 4.23 +/- 0.85 pg . ml(-1).degrees C-1, significantly higher than the 1.68 +/- 1.10 pg . ml(-1).degrees C-1 increase at a P-osm of 284 +/- 1 mosmol/kgH(2)O. Our data indicate that the effect of increased T-es and P-osm on [AVP](p) is not simply additive but P-osm dependent. We conclude that increased T-es modulates osmotically induced AVP secretion in a P-osm-dependent manner., 1995年10月, 269, 4, R874, R880, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, OSMOREGULATORY MODULATION OF THERMAL SWEATING IN HUMANS - REFLEX EFFECTS OF DRINKING, A TAKAMATA; GW MACK; CM GILLEN; AC JOZSI; ER NADEL, To gain better insight into the interaction between thermoregulation and osmoregulation, we examined the thermal sweating response to drinking in cell-dehydrated humans. Cell dehydration (CDH) was induced by infusion of a 3% NaCl solution, at 1.2 ml/kg, for 2 h; infusion of a 0.9% NaCl solution in a separate experiment served as a control (euhydrated condition, EH). After infusion, subjects were heated by immersion of the lower legs in 42 degrees C water at an ambient temperature of 28 degrees C for 90 min. Subjects drank 4.3 ml/kg of H2O (similar to 38 degrees C) at 60 min of heating. The 3% NaCl infusion increased plasma osmolality by 13.6 +/- 0.8 mosmol/kgH(2)O and plasma arginine vasopressin concentration ([AVP]) by 3.3 +/- 0.7 pg/ml. Neither variable was altered with 0.9% NaCl infusion. Before drinking, esophageal temperature (T-es) had increased by 0.91 +/- 0.08 degrees C in CDH and by 0.40 +/- 0.11 degrees C in EH. Local chest sweating rate (SR(ch)) had increased by 0.67 +/- 0.08 and 0.63 +/- 0.07 mg . min(-1) . cm(-2) in CDH and EH, respectively. Thus the change in SR(ch) per unit rise in T-es was much lower in CDH than in EH. Drinking immediately increased SR(ch) and reduced T-es in CDH, with a reduction in plasma [AVP] and thirst rating. Drinking did not change thermoregulatory and osmoregulatory responses in EH. These results suggest that the act of drinking itself eliminates, at least partially, an osmotic inhibitory input to the thermoregulatory center, as well as osmotic AVP secretion and thirst., 1995年02月, 268, 2, R414, R422, 研究論文(学術雑誌)
  • 査読無し, 英語, JOURNAL OF APPLIED PHYSIOLOGY, RIGHT ATRIAL PRESSURE AND ANP RELEASE DURING PROLONGED EXERCISE IN A HOT ENVIRONMENT, H NOSE; A TAKAMATA; GW MACK; T KAWABATA; Y ODA; S HASHIMOTO; M HIROSE; E CHIHARA; T MORIMOTO, To investigate the relationship between right atrial pressure (RAP) and atrial natriuretic peptide (ANP) release during prolonged exercise in a hot environment (30 degrees C, 20% relative humidity), we studied with a Swan-Ganz catheter five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min. The ANP level increased from 14 +/- 3 (SE) to 69 +/- 10 pg/ml (P < 0.001) during the first 10 min of exercise as RAP rose from 4.3 +/- 0.8 to 6.9 +/- 1.1 mmHg (P < 0.001). The 10-min ANP level was significantly correlated with RAP (r = 0.88, P < 0.05) but not with heart rate, pulmonary arterial blood temperature, plasma norepinephrine, or plasma epinephrine. The 10-min RAP value was inversely correlated with blood volume (r = -0.98, P < 0.01) and also with stroke volume (r = -0.96, P < 0.01). In the next 20 min of exercise, ANP continued to increase to 101 +/- 12 pg/ml (P < 0.02 vs. 10 min) and remained at this level until 50 min of exercise, whereas RAP decreased and reached a level not significantly different from baseline at 50 min (5.7 +/- 1.0 mmHg; P < 0.01 vs. 10 min). This dissociation of ANP and RAP may have been related to the significant increases from the 10-min values of heart rate, blood temperature, norepinephrine (all P < 0.01), and epinephrine (P < 0.02) during the same period. These results suggest that ANP release is primarily controlled by atrial distension at the onset of exercise but that other stimulators may be involved thereafter. The lower ANP release in subjects with a higher blood volume at 10 min may have been caused by an attenuated increase in RAP due to a larger stroke volume., 1994年05月, 76, 5, 1882, 1887, 研究論文(学術雑誌)
  • 査読無し, 英語, AMERICAN JOURNAL OF PHYSIOLOGY, SODIUM APPETITE, THIRST, AND BODY-FLUID REGULATION IN HUMANS DURING REHYDRATION WITHOUT SODIUM REPLACEMENT, A TAKAMATA; GW MACK; CM GILLEN; ER NADEL, After a 7-h H2O and Na+ depletion period (DP), produced by intermittent light exercise (8 bouts) at 35 degrees C, we examined thirst and taste palatability responses to 10 different NaCl solutions during 23 h of rehydration (RH) at 25 degrees C. During DP, net H2O and Na+ loss were 27.2 +/- 2.9 ml/kg and 3.29 +/- 0.45 meq/kg, respectively. Plasma osmolality (P-Osm) and plasma Na+ concentration ([Na+](p)) increased significantly during DP by 3.4 +/- 1.2 mosmol/kgH(2)O and 3.0 +/- 1.0 meq/kgH(2)O, respectively. Plasma volume (PV) decreased by 6.5 +/- 1.9%. Thirst rating, renal fractional reabsorption of H2O, and plasma arginine vasopressin concentration (P-AVP) increased as P-Osm increased. This increased thirst was accompanied by increased palatability ratings to H2O. During RH, subjects drank deionized H2O ad libitum and ate a Na+-free diet for 23 h. P-Osm and [Na+](p) returned to control levels within 1 h RH and remained at or below the control thereafter. PV remained reduced by similar to 5% throughout RH. The increased thirst and P-AVP returned to their respective control levels within 1 h of RH as P-Osm decreased, but thirst rating increased again between 17 and 23 h of RH without an increase in P-Osm or P-AVP. Palatability ratings to a 1 M NaCl solution at and after 3 h RH and palatability ratings to 0.3 M at 17 and 23 h RH were significantly higher than control. Plasma aldosterone concentration (P-Aldo) increased after DP, decreased with drinking, and increased again between 6 and 23 h of RH, accompanied by a marked decrease in fractional Na+ excretion to <0.07%. Thus both Na+ preference and thirst in humans are influenced by body fluid and electrolyte status. The increased Na+ palatability (Na+ appetite) was preceded by osmotically induced thirst, and accompanied by nonosmotically driven thirst [extracellular fluid (ECF) thirst] and increased P-Aldo. The ''Na+ appetite'' and ''ECF thirst'' along with increased renal Na+ retention could contribute to ECF volume regulation after thermally induced H2O and Na+ depletion., 1994年05月, 266, 5, R1493, R1502, 研究論文(学術雑誌)
  • 査読無し, 英語, PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, RIGHT ATRIAL PRESSURE AND FOREARM BLOOD-FLOW DURING PROLONGED EXERCISE IN A HOT ENVIRONMENT, H NOSE; A TAKAMATA; GW MACK; Y ODA; T KAWABATA; S HASHIMOTO; M HIROSE; E CHIHARA; T MORIMOTO, Right atrial pressure (RAP) at rest is known to be reduced by an increase in skin blood flow (SkBF) in a hot environment. However, there is no clear evidence that this is so during exercise. To clarify the effect of the increase in SkBF on RAP during exercise, we measured forearm blood flow (FBF) (as an index of SkBF) and RAP continuously using a Swan-Ganz catheter in five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min in a hot environment (30 degrees C, relative humidity 20%). Cardiac output increased from 5.5 +/- 0.2 l/min at rest to 17.9 +/- 1.2 l/min (mean +/- SE, P < 0.01) in the first 10 min of exercise and then remained steady until the end of exercise. FBF did not change significantly during the first 5 min, but then increased from 2.7 +/- 0.5 ml/100 ml per min at rest to 10.8 +/- 1.7 ml/100 ml per min (P < 0.001) by 25 min as pulmonary arterial blood temperature (T-b) rose from 37.0 +/- 0.1 degrees C to 38.1 +/- 0.1 degrees C (P < 0.001). FBF then reached a plateau, despite a continuing increase in T,. RAP increased significantly from 4.3 +/- 0.8 to 7.6 +/- 1.2 mm Hg (P < 0.001) during the first 5 min of exercise and then gradually declined to 6.1 +/- 1.0 mm Hg by 25 min (P < 0.001 vs. 5 min) and further to 5.7 +/- 1.0 mm Hg by 50 min, a value not significantly higher than at rest. This reduction in RAP during exercise was significantly correlated with the increase in FBF (r = -0.97, P < 0.001) with a regression equation of RAP = -0.25XFBF + 8.8. These results suggest that the decrease in RAP after 5 min exercise was caused by an increase in SkBF during exercise in a hot environment., 1994年02月, 426, 3-4, 177, 182, 研究論文(学術雑誌)
  • 査読無し, 英語, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, INFLUENCE OF EXERCISE INTENSITY AND PLASMA-VOLUME ON ACTIVE CUTANEOUS VASODILATION IN HUMANS, GW MACK; H NOSE; A TAKAMATA; T OKUNO; T MORIMOTO, The influence of dynamic exercise on active cutaneous vasodilation was evaluated in eight male subjects. We measured the increase in internal body temperature (esophageal temperature, T-es) required to elicit active cutaneous vasodilation and the slope of the linear relationship between increases in forearm skin vascular conductance (Delta FVC) and T-es during indirect heating (legs immersed in 44 degrees C water for 30 min), 30 min of light exercise (LEX; 75 +/- 5 W = 30% maximal oxygen uptake, VO2max), and 20 min of moderate exercise (MEX, 149 +/- 7 W = 60% VO2max) Studies were conducted in the supine position at 30 degrees C (RH <30%) and mean skin temperature averaged 35.09 +/- 0.12 degrees C. During indirect heating and LEX, cutaneous vasodilation occurred after a similar increase in T-es, 0.03 +/- 0.02 degrees C and 0.11 +/- 0.02 degrees C, respectively. During MEX, T-es increased 0.42 +/- 0.06 degrees C before the onset of cutaneous vasodilation (P < 0.05, different from rest and LEX). The relationship between the increase in T-es threshold for vasodilation and exercise intensity was nonlinear, indicating that some minimal exercise intensity was required to elicit a delay in active cutaneous vasodilation. That minimal exercise intensity was greater than 30% VO2max (75 +/- 5 W). During MEX the increase in T-es threshold for vasodilation was inversely related to resting plasma volume (ml . kg(-1)) with a larger initial plasma volume associated with a smaller increase in T-es threshold for cutaneous vasodilation (r(2) = 0.67, P = 0.03). In addition, peak cutaneous vasodilation represented as the peak Delta FVC/peak Delta T-es, was directly related to plasma volume (r(2) = 0.64, P = 0.03). We conclude that the influence of exercise on the threshold for active cutaneous vasodilation is dependent on an interaction between exercise intensity and the size of the intravascular compartment. This conclusion is consistent with the hypothesis that blood volume expansion is an important adaptation of exercise training and contributes to improved thermoregulatory control during exercise in the heat., 1994年02月, 26, 2, 209, 216, 研究論文(学術雑誌)
  • 査読無し, 英語, JOURNAL OF APPLIED PHYSIOLOGY, MEASUREMENT OF PLASMA-VOLUME IN RATS WITH USE OF FLUORESCENT-LABELED ALBUMIN MOLECULES, CM GILLEN; A TAKAMATA; GW MACK; ER NADEL, We describe a method for measuring plasma volume (PV) in small animals that allows small sample sizes but does not require the use of radioisotopes and thus is a convenient approach for making repeated measurements. Texas Red covalently bound to albumin (TR-A) was used in a typical indicator-dilution technique to measure PV. The relative fluorescent intensity of TR-A is linear to its concentration (up to 0.15 mg/ml) at an excitation lambda of 590 nm and an emission lambda of 610 nm. Catheters were inserted through the right jugular vein of anesthetized rats and threaded into the vena cava. A 0.5-ml control blood sample was taken, a measure quantity of TR-A was injected, and the catheter was flushed with saline. A 0.5-ml postinjection sample was taken 5 min after TR-A injection. PV was calculated by comparing the difference between the relative fluorescent intensity of control and postinjection plasma samples to a standard. The PV of 22 rats [362 +/- 14 (SE) g] was 14.1 +/- 0.4 ml (39.6 +/- 0.9 ml/kg body wt) measured by the TR-A method and 12.8 +/- 0.4 ml (35.9 +/- 1.0 ml/kg body wt) measured by a standard radioiodinated albumin method. There was a strong correlation between PV measured by both methods in the same rat (r = 0.90, P < 0.01). Infusion experiments indicated that the TR-A method can detect acute changes in PV, and repeated measurements of PV made on a chronically instrumented rat demonstrated that the method can reliably measure PV on consecutive days., 1994年01月, 76, 1, 485, 489
  • 査読無し, 英語, JAPANESE JOURNAL OF PHYSIOLOGY, EFFECT OF VAGOTOMY ON CARDIOVASCULAR ADJUSTMENT TO HYPERTHERMIA IN RATS, A TAKAMATA, To elucidate the contribution of cardiopulmonary baroreflexes on the control of total peripheral vascular conductance (TVC) during hyperthermia, alpha-chloralose-anesthetized rats with (VX-groups) or without (C-groups) vagotomy were subjected to body heating raising arterial blood temperature (T(b)) at a rate of 0.1-degrees-C/min. In both the C- and VX-groups, rats were divided into normovolemia (C-NBV and VX-NBV) and furosemide-induced hypovolemia (C-LBV and VX-LBV) and cardiovascular responses to hyperthermia were compared between the four groups. Central venous pressure (CVP) decreased as T(b) rose to 43-degrees-C by 1.92 +/- 0.24, 1.36 +/- 0.28, 0.62 +/- 0.14, and 0.35 +/- 0.23 mmHg in the C-NBV, VX-NBV, C-LBV, and VX-LBV groups, respectively. Mean arterial pressure increased by 35-45 mmHg in the C-groups and by 25-35 mmHg in the VX-groups at T(b) of 42-43-degrees-C in the C-groups and 42-degrees-C in the VX-groups. Heart rate response to increased T(b) was not affected by vagotomy or LBV. Stroke volume correlated with CVP (r = 0.769) and this relationship did not differ among the four groups. TVC was more highly correlated with CVP in the C-groups (r = 0.925) than in the VX-groups (r = 0.757). The slope of TVC vs. CVP (TVC/CVP) for the VX-groups lowered by about 40% from that for the C-groups. These results suggest that during hyperthermia, cardiopulmonary baroreflexes may partly contribute to the control of TVC, and other mechanisms related to decreased BV and increased T(b) play some roles in the control of TVC., 1992年, 42, 4, 641, 652, 研究論文(学術雑誌)
  • 査読無し, その他, 京都府立医科大学雑誌, 低酸素負荷による睡眠時血圧動揺の解析, 鷹股 亮; 仲井幹雄; 能勢博; 猪田浩史; 陳勉; 鷹股亮; 池内隆治; 森本武利, 1992年, 101, 625, 633
  • 査読無し, 英語, JOURNAL OF APPLIED PHYSIOLOGY, WATER AND ELECTROLYTE BALANCE IN THE VASCULAR SPACE DURING GRADED-EXERCISE IN HUMANS, H NOSE; A TAKAMATA; GW MACK; Y ODA; T OKUNO; DH KANG; T MORIMOTO, We analyzed the changes in water content and electrolyte concentrations in the vascular space during graded exercise of short duration. Six male volunteers exercised on a cycle ergometer at 20-degrees-C (relative humidity = 30%) as exercise intensity was increased stepwise until voluntary exhaustion. Blood samples were collected at exercise intensities of 29, 56, 70, and 95% of maximum aerobic power (Vo2max). A curvilinear relationship between exercise intensity and Na+ concentration in plasma ([Na+]p) was observed. [Na+]p significantly increased at 70% Vo2max and at 95% Vo2max was approximately 8 meq/kgH2O higher than control. The change in lactate concentration in plasma ([Lac-]p) was closely correlated with the change in [Na+]p (DELTA[Na+]p = 0.687 DELTA[Lac-]p + 1.79, r = 0.99). The change in [Lac-]p was also inversely correlated with the change in HCO3- concentration in plasma (DELTA[HCO3-]p = -0.761 DELTA[Lac-]p + 0.22, r = -1.00). At an exercise intensity of 95% Vo2max, 60% of the increase in plasma osmolality (Posmol) was accounted for by an increase in [Na+]p. These results suggest that lactic acid released into the vascular space from active skeletal muscles reacts with [HCO3-]p to produce CO2 gas and Lac-. The data raise the intriguing notion that increase in [Na+]p during exercise may be caused by elevated Lac-., 1991年06月, 70, 6, 2757, 2762, 研究論文(学術雑誌)
  • 査読あり, 英語, Journal of Applied Physiology, Water and electrolyte balance in the vascular space during graded exercise in humans, H. Nose; A. Takamata; G. W. Mack; Y. Oda; T. Okuno; D. H. Kang; T. Morimoto, We analyzed the changes in water content and electrolyte concentrations in the vascular space during graded exercise of short duration. Six male volunteers exercised on a cycle ergometer at 20°C (relative humidity = 30%) as exercise intensity was increased stepwise until voluntary exhaustion. Blood samples were collected at exercise intensities of 29, 56, 70, and 95% of maximum aerobic power (V̇O(2 max)). A curvilinear relationship between exercise intensity and Na+ concentration in plasma ([Na+]p) was observed. [Na+]p significantly increased at 70% V̇O(2 max) and at 95% V̇O(2 max) was ~8 meq/kgH2O higher than control. The change in lactate concentration in plasma ([Lac-]p) was closely correlated with the change in [Na+]p (Δ[Na+]p = 0.687 Δ[Lac-]p + 1.79,r = 0.99). The change in [Lac-]p was also inversely correlated with the change in HCO-/3 concentration in plasma (Δ[HCO-/3]p = -0.761 Δ[Lac-]p + 0.22, r = -1.00). At an exercise intensity of 95% V̇O(2 max), 60% of the increase in plasma osmolality (Posmol) was accounted for by an increase in [Na+]p. These results suggest that lactic acid released into the vascular space from active skeletal muscles reacts with [HCO-/3]p to produce CO2 gas and Lac-. The data raise the intriguing notion that increase in [Na+]p during exercise may be caused by elevated Lac-., 1991年, 70, 6, 2757, 2762, 研究論文(学術雑誌)
  • 査読無し, 英語, JOURNAL OF APPLIED PHYSIOLOGY, CONTROL OF TOTAL PERIPHERAL RESISTANCE DURING HYPERTHERMIA IN RATS, A TAKAMATA; H NOSE; GW MACK; T MORIMOTO, 1990年09月, 69, 3, 1087, 1092, 研究論文(学術雑誌)
  • 査読あり, 英語, Journal of Applied Physiology, Control of total peripheral resistance during hyperthermia in rats, A. Takamata; H. Nose; G. W. Mack; T. Morimoto, To elucidate the effect of blood volume on the circulatory adjustment to heat stress, we studied α-chloralose-anesthetized rats at three levels of blood volume: normovolemia (NBV), hypervolemia (HBV +32% plasma volume by isotonic albumin solution infusion), and hypovolemia (LBV -16% plasma volume by furosemide administration). Body surface heating was performed with an infrared lamp to raise arterial blood temperature (T(b)) at the rate of ~0.1°C/min. Before heating, central venous pressure (CVP) was significantly higher in HBV (0.41 ± 0.25 mmHg) and lower in LBV (-1.44 ± 0.22 mmHg) than in NBV (-0.41 ± 0.10 mmHg). The T(b) at which CVP started to decrease was ~40°C in HBV, ~41°C in NBV, and ~42°C in LBV, and it decreased by 1.53 ± 0.14, 1.92 ± 0.24, and 0.62 ± 0.14 mmHg from 37 to 43°C of T(b) in HBV, NBV, and LBV, respectively. Stroke volume was closely correlated with CVP, and this relationship was not affected by T(b). Heart rate responses to the raised T(b) were similar among the three groups. Mean arterial pressure (MAP) was not affected by blood volume modification or CVP and was maintained at preheating (T(b) 37°C) level until T(b) rose to 40°C. Above this T(b), MAP increased until T(b) reached 43°C (+30-40 mmHg) for all three groups. Total peripheral resistance (TPR) was inversely correlated with CVP, and the slope of the linear relationship between TPR and CVP in LBV was three- to fourfold steeper than in NBV or HBV. These results suggest that the control of TPR during severe hyperthermia (T(b) > 40°C) is influenced by T(b) and also by a cardiopulmonary baroreflex in response to a fall in CVP., 1990年, 69, 3, 1087, 1092, 研究論文(学術雑誌)
  • 査読無し, その他, アルコール代謝と肝, 遊泳運動による摂取エタノールの生体内分布の変動と体温調節反応, 鷹股 亮; 今泉和彦; 立屋敷かおる; 鷹股亮; 荻田善一, 1988年, 7, 85, 93
  • 査読無し, 日本語, 日本栄養・食糧学会誌, Japan Society of Nutrition and Food Science, 血漿エタノールレベルの日内変動に対する胃内容物の役割―in vivo レベルの検討―, 鷹股 亮; 立屋敷かおる; 今泉和彦; 戸田典子; 鷹股亮; 上杉公仁子; 荻田善一, 無制限給餌 (水) 下で飼育したラットにエタノール (EtOH) を経口投与し, そのEtOH代謝に対する日内変動の有無を定量的に明らかにする目的で研究を行なった。そのため, 8: 00と20: 00にEtOHを投与し, その血漿EtOH濃度 (p [EtOH]) の経時変化を測定し解析した。また, EtOH投与前12時間にラットが摂取した餌と水の重量を測定し, これらの各量とp [EtOH] の関係をしらべた。さらに, p [EtOH] が消失した直後に, 胃内 [EtOH] と胃内容物重量を測定した。SpragueDawley系雌ラット (184±10g) を温度25±2℃, 湿度50~60%の条件で飼育し, 20: 00に消灯し, 8: 00に点灯するようにセットした。ラットにはEtOH投与直前まで任意に餌と水を与えた。投与EtOH量は100mg/100g体重 (20%EtOH溶液) とした。その結果, 以下の結論を得た。
    1) 20: 00から8: 00まで (暗期) と8: 00から20: 00まで (明期) の摂餌量は, おのおの5.7±1.6, 1.6±0.7mg・g-1B.W. ・hr-1である。前者は後者の約3.6倍である。摂水量は暗期が明期に比べて約2.2倍大きい。したがって, ラットの摂餌量と摂水量はともに暗期が明期に比べて有意に大きい。
    2) 20: 00にEtOHを投与して得られたp [EtOH] の最大値 (A), Aに達するまでの時間 (B), 血漿EtOHの消失時間 (C) および血漿EtOHの積分値 (D) は, 8: 00のEtOH投与で得られたA, B, C, Dの値に比べおのおの2.0, 1.5, 1.6, 3.2倍となり, 有意に高い。したがって, 無制限給餌下で飼育したラットのp [EtOH] の経時過程に, みかけ上の日内変動が明らかに認められる。しかし, EtOHの消失速度定数 (k) 値には暗期と明期で差がみられない。この現象が, 代謝レベルによるのか, または他の生理的特性と関係があるのかを明らかにするため, さらに解析した。
    3) 肝細胞質内の肝ADH比活性値は, 8: 00と20: 00にEtOHを投与したグループとの間に有意な差が認められず, 日内変動はみられない。したがって, EtOH分解能は両群の間に差がない。
    4) 胃内容物重量と胃内 [EtOH] から求めた胃内Et-OH残存率は, 8: 00投与の実験で25.8±10.7%, 20: 00投与の場合で0.3±0.4%である。前者が後者に比べて約86倍大きく, 日内変動が明らかにみられる。
    5) p [EtOH] の経時過程から得られた各パラメータ (A~D) 値と胃内容物重量または胃内EtOH量との間には, 高い負の相関が認められ, ほぼ逆比例の関係が成立する。
    以上の結果より, ラットのp [EtOH] の経時過程に著しい日内変動が認められるのは, 胃内容物量の多少により, 投与されたEtOHの胃内残存率が大きく変化し, 血漿へのEtOHの移行も大きく変動するためと推定できる。, 1987年, 40, 1, 35, 42
  • 査読無し, その他, アルコール代謝と肝, エタノールの生体内分布の動的解析, 鷹股 亮; 今泉和彦; 立屋敷かおる; 鷹股亮; 戸田典子; 蒲田直明, 1987年, 6, 66, 74
  • 査読無し, その他, アルコール代謝と肝, 肝エタノール代謝に及ぼす運動の影響, 鷹股 亮; 今泉和彦; 立屋敷かおる; 佐々木友子; 長野肇; 大滝優子; 鷹股亮, 1986年, 5, 242, 250
  • 査読あり, 英語, Physiological reports, Estradiol replacement improves high-fat diet-induced insulin resistance in ovariectomized rats., 2022年03月, 10, 5, e15193
  • 日本語, 日本臨床麻酔学会誌, THE JAPAN SOCIETY FOR CLINICAL ANESTHESIA, 麻酔・手術と体液代謝 体液浸透圧変化の循環調節に及ぼす影響, 能勢 博; 広瀬 宗孝; 中嶋 康文; 鷹股 亮; 陳 勉, 1997年, 17, 10, 585, 588

MISC

  • 査読無し, その他, デサントスポーツ科学, 運動時の全身循環および体温調節機能をサポートする下肢圧迫法の開発, 鷹股 亮; 鷹股亮, 2005年, 24, 95, 102
  • 査読無し, 日本語, デサントスポーツ科学, 石本記念デサントスポ-ツ科学振興財団事務局, 運動トレーニングおよび暑熱馴化時の体温調節機能の亢進における浸透圧調節系の役割, 鷹股 亮; 鷹股亮; 芳田哲也, 1998年, 19, 19, 116, 123
  • 査読無し, 日本語, 宇宙利用シンポジウム, 静脈還流量からみた微小重力下での循環調節, 森本武利; 永島計; 能勢博; 鷹股亮, 1996年09月, 13th, 55, 58
  • 査読無し, 日本語, 長崎大学熱帯医学研究所共同研究報告集, 中心静脈圧と体温調節反応 (長崎大学熱帯医学研究所S), 永島計; 能勢博; 鷹股亮; 森本武利, 1996年06月30日, 1995, 136
  • 査読無し, その他, 小野スポーツ科学, 血漿浸透圧の上昇が温熱負荷時の皮膚血流調節に及ぼす影響とその個人差, 鷹股 亮; 鷹股亮; 永島計; 能勢博, 1996年, 4, 109, 122
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Estradiol-modification of Blood Pressure Regulatory Response to Systemic and Central Angiotensin II Administration in Rats, Akira Takamata; Natsumi Omura; Yuri Nishimura; Ayako Igarashi; Keiko Morimoto, 2015年04月, 29, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Estradiol Replacement Attenuates Central Body Fluid Regulatory Responses to Hyperosmolality and Central Angiotensin II in Ovariectomized Rats, Natsumi Omura; Yuri Nishimura; Ayako Igarashi; Akira Takamata, 2015年04月, 29, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Effect of Estradiol Replacement on Diurnal Sleep/Wake Pattern in Ovariectomized Rats Measured with a Subcutaneously Implanted Acceleration Sensor, Ayako Igarashi; Natsumi Omura; Megumi Miura; Nanako Mima; Yuri Nishimura; Kaori Mabuchi; Akira Takamata, 2015年04月, 29, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, The effects of menstrual phase on brachial artery endothelial function after mental stress in young women, Xin Chen; Kyoko Ueshima; Mika Omokute; Akira Takamata; Keiko Morimoto, 2015年04月, 29, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Estradiol replacement attenuates stress-induced pressor response by regulating renin-angiotensin system in ovariectomized rats, Yu Nagatomo; Shoko Tazumi; Risa Itoh; Misa Yoshimoto; Akira Takamata; Keiko Morimoto, 2015年04月, 29, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Serotonin is possibly involved in the anorexigenic and antidepressant effects of estrogen in ovariectomized rats, Yuri Nishimura; Kaori Mabuchi; Hiroko Negishi; Keiko Morimoto; Akira Takamata, 2013年04月, 27, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Orchiectomy increases food intake and perifornical orexin A neuron's activity during glucoprivation, Akira Takamata; Kana Miyake; Kaori Mabuchi; Keiko Morimoto, 2013年04月, 27, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER JAPAN KK, Removal of photic stimulation impairs estrogen-induced anorexia in rats, Kaori Mabuchi; Azusa Takano; Yayoi Hara; Keiko Morimoto; Akira Takamata, 2013年, 63, S255, S255, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Orexigenic and obesity effects of estrogen deficiency can be attenuated by half-day food deprivation either during the light phase or the dark phase, Sayumi Taguchi; Kaori Mabuchi; Azusa Takano; Yayoi Hara; Keiko Morimoto; Akira Takamata, 2012年04月, 26, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Involvement of orexin A and melanin concentrating hormone neurons of the lateral hypothalamic area in the food intake response to reduced glucose availability, Akira Takamata; Sayumi Taguchi; Saori Ikeda; Eri Aida; Keiko Morimoto, 2012年04月, 26, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, EUROPEAN JOURNAL OF ANAESTHESIOLOGY, LIPPINCOTT WILLIAMS & WILKINS, Effect of central angiotensin II receptor antagonist and endogenous vasopressin on blood pressure regulation during normotension endotoxemia in rats, F. Shimizu; T. Kasai; S. Inoue; A. Takamata, 2010年06月, 27, 1, 171, 171, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, Estrogen attenuates food intake and hypothalamic c-Fos expression in response to reduced glucose availability during light phase, Akira Takamata; Kana Miyake; Kotomi Ueda; Mami Miyake; Megumu Hasegawa; Yuko Nakamura; Yoko Fujita; Keiko Morimoto, 2010年, 60, S181, S181, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, Roles of oxidative stress on the reduction of forearm blood flow induced by mental stress in postmenopausal women, Keoko Morimoto; Kozue Ohyama; Mai Motohiro; Shigenobu Yano; Akira Takamata, 2010年, 60, S58, S58, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Role of light in the estrogen deficiency-induced changes in diurnal SCN neural activity and food intake, Kana Miyake; Keiko Morimoto; Akira Takamata, 2009年04月, 23, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Estrogen attenuates food intake and perifornical orexinergic neuron's activity during glucoprivation in ovariectomized rats, Akira Takamata; Kana Miyake; Keiko Morimoto, 2009年04月, 23, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, EFFECTS OF ESTROGEN REPLACEMENT ON OXIDATIVE STRESS IN VASCULATURE RELATED TO PSYCHOLOGICAL STRESS IN OVARIECTOMIZED RATS, Ai Ikehata; Mizuho Kawakami; Sumire Ohkawa; Asumi Yoshida; Masami Uji; Akira Takamata; Ken-ichi Yoshida; Keiko Morimoto, 2009年, 59, 497, 497, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, EFFECTS OF ESTROGEN ON STRESS-INDUCED ACTIVATION OF NITRIC OXIDE PRODUCING NEURONS IN PARAVENTRICULAR HYPOTHALAMIC NUCLEUS OF RATS, Yurina Omuro; Tomoko Hata; Yasuko Hara; Akira Takamata; Takashi Ueyama; Keiko Morimoto, 2009年, 59, 333, 333, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, ESTROGEN DEFICIENCY MODIFIES DIURNAL RHYTHMS OF SCN ACTIVITY AND BEHAVIORS BY CHANGING THE RESPONSE TO LIGHT, Kana Miyake; Yuka Kobayashi; Keiko Morimoto; Akira Takamata, 2009年, 59, 333, 333, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, PEAK OXYGEN UPTAKE DOES NOT CORRELATE WITH BLOOD VOLUME IN PERSONS WITH CERVICAL SPINAL CORD INJURY, Tomoyuki Ito; Yukiharu Higuchi; Yumi Koike; Kazunobu Okazaki; Sumiko Shiba; Takahiro Miyake; Hiroyasu Uenishi; Akira Takamata; Hiromitsu Kimura; Fumihiro Tajima, 2009年, 59, 455, 455, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, ESTROGEN ATTENUATES RESPONSES OF FOOD INTAKE AND PERIFORNICAL OREXINERGIC NEURON'S ACTIVITY TO GLUCOPRIVATION, Akira Takamata; Kana Miyake; Yoko Fujita; Yuko Nakamura; Yuka Kobayashi; Keiko Morimoto, 2009年, 59, 458, 458, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Effect of estrogen replacement on food intake and hypothalamic c-Fos expression in ovariectomized rats, A Takamata; Y Saito; R Kobayashi; K Torii; K Morimoto, 2005年03月, 19, 5, A1647, A1647, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Effect of estrogen replacement on water intake and hypothalamic c-Fos expression induced by plasma hyperosmolality or central angiotensin II in ovariectomized rats, K Torii; Y Kitamura; K Morimoto; A Takamata, 2005年03月, 19, 5, A1647, A1648, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Cardiovascular and ventilatory responses during and after exercise in persons with cervical spinal cord injuries, T Ito; Y Higuchi; H Banno; T Mizushima; A Takamata; H Kimura; F Tajima, 2003年03月, 17, 5, A941, A941, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Relationship between osmotic inhibition of thermoregulatory responses and sweat sodium concentration., A Takamata; T Yoshida; T Morimoto, 2000年03月, 14, 4, A321, A321, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, ANESTHESIOLOGY, LIPPINCOTT WILLIAMS & WILKINS, Cardiopulmonary baroreceptor modulation of perioperative hypothermia, Y Nakajima; T Mizobe; K Hayashi; Y Kitamura; K Shigemi; A Takamata; Y Tanaka, 1998年09月, 89, 3A, U296, U296, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Effect of heat acclimation on body fluid regulation in older subjects., A Takamata; T Ito; K Yaegashi; H Takamiya; Y Maegawa; T Itoh; T Morimoto; JE Greenleaf, 1998年03月, 12, 4, A125, A125, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, Effect of plasma osmolality on thermoregulatory responses to passive heating in humans, A Takamata; K Nagashima; H Nose; T Morimoto, 1996年03月, 10, 3, 681, 681, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, BODY-TEMPERATURE INFLUENCE ON OSMOTICALLY INDUCED VASOPRESSIN SECRETION IN HUMANS, GW MACK; A TAKAMATA; NS STACHENFELD; ER NADEL, 1995年03月, 9, 4, A632, A632, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, ACUTE RECOVERY OF OSMOTICALLY INHIBITED SWEATING IN HUMANS BY DRINKING, A TAKAMATA; GW MACK; CM GILLEN; AC JOZSI; ER NADEL, 1994年03月, 8, 4, A65, A65, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, FLUID REGULATION DURING EXTREME CELL DEHYDRATION IN OLDER ADULTS, N STACHENFELD; G MACK; A TAKAMATA; L DIPIETRO; E NADEL, 1994年03月, 8, 5, A588, A588, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, BIPHASIC THIRST RESPONSE IN HUMANS FOLLOWING THERMAL EXERCISE SWEATING WITHOUT SODIUM REPLENISHMENT, A TAKAMATA; GW MACK; CM GILLEN; ER NADEL, 1993年02月, 7, 3, A444, A444, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, MEASUREMENT OF PLASMA-VOLUME IN RATS USING FLUORESCENT-LABELED ALBUMIN MOLECULES, CM GILLEN; A TAKAMATA; GW MACK; ER NADEL, 1993年02月, 7, 3, A444, A444, 研究発表ペーパー・要旨(国際会議)
  • 査読無し, 英語, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL, CHANGE IN RIGHT ATRIAL PRESSURE DURING EXERCISE AND THE EFFECT ON THERMAL AND CIRCULATORY REGULATIONS, H NOSE; A TAKAMATA; G MACK; Y ODA; S HASHIMOTO; M HIROSE; E CHIHARA; T MORIMOTO, 1991年03月, 5, 5, A1400, A1400, 研究発表ペーパー・要旨(国際会議)
  • 日本語, 人間科学研究, 神戸大学, 浸透圧調節機構と体温調節機構の相互作用 : 体液調節と体温調節の相互作用 : 運動トレーニング・暑熱順化と加齢の影響(高齢者の発達を支援する環境づくり(3) : 人間環境科学科研究プロジェクト 人間科学研究センター発達環境研究プロジェクト), 鷹股 亮, 2002年11月, 10, 1, 141, 158
  • 日本語, 体力科學, 日本体力医学会, 166.高齢者の暑熱順化による水分出納および口渇感の変化, 岡山 寧子; 木村 みさか; 鷹股 亮; 伊藤 倫之; 永井 由香; 森本 武利, 2000年12月01日, 49, 6, 749, 749
  • 日本語, 体力科學, 日本体力医学会, 358.血漿浸透圧上昇による体温調節反応の抑制と汗ナトリウム濃度との関係, 鷹股 亮; 森本 武利, 1998年12月01日, 47, 6, 881, 881
  • 日本語, 体力科學, 日本体力医学会, 604.運動時の皮膚血管拡張反応における血漿浸透圧の役割, 鷹股 亮; 森本 武利; 能勢 博, 1997年12月01日, 46, 6, 914, 914
  • 日本語, 体力科學, 日本体力医学会, 251.温熱性皮膚血管拡張閾値に対する血漿浸透圧の影響, 鷹股 亮; 能勢 博; 芳田 哲也; 森本 武利, 1995年12月01日, 44, 6, 732, 732
  • 日本語, 体力科學, 日本体力医学会, 55.高温環境下循環調節における中心静脈圧の役割 : 生物科学I (呼吸・循環,代謝など), 鷹股 亮; 能勢 博; 森本 武利, 1989年12月01日, 38, 6, 305, 305
  • 英語, 体力科學, 日本体力医学会, 382.遊泳運動による摂取エタノールの生体内分布の変動と体温調節反応 : 温度依存性の解析 : 代謝,加齢,女子, 鷹股 亮; 立屋敷 かおる; 今泉 和彦, 1990年12月01日, 39, 6, 804, 804
  • 日本語, 体力科學, 日本体力医学会, 370.運動強度と脈管内外の水分塩分バランス : 神経,感覚,体液,内分泌, 能勢 博; 鷹股 亮; G W Mack; 小田 慶喜; 奥野 直; 姜 徳鎬; 森本 武利, 1990年12月01日, 39, 6, 792, 792
  • 日本語, 体力科學, 日本体力医学会, 139.血圧調節に血漿浸透圧、体温が及ぼす影響(【呼吸・循環】), 伊藤 倫之; 鷹股 亮, 2001年12月01日, 50, 6, 802, 802
  • 日本語, 日本生気象学会雑誌, 唐辛子湯が下腿温浴時の体温および発汗に及ぼす影響, 鷹股 亮; 西田 直子; 森本 武利, 1999年01月29日, 35, 3, S69
  • 日本語, 体力科學, 日本体力医学会, 156.灌流圧低下が運動時の骨格筋血流に及ぼす影響(呼吸・循環,一般口演,第60回 日本体力医学会大会), 川本 麻理子; 森本 恵子; 鷹股 亮, 2005年12月01日, 54, 6, 496, 496
  • 日本語, 体力科學, 日本体力医学会, 155.精神性ストレス及び運動負荷時の昇圧反応に及ぼす月経周期や閉経の影響(呼吸・循環,一般口演,第60回 日本体力医学会大会), 森本 恵子; 森川 真悠子; 鷹股 亮, 2005年12月01日, 54, 6, 496, 496
  • 日本語, 体力科學, 日本体力医学会, 188.エストロゲン補充が卵巣摘出ラットの摂取行動、活動量、体温の日内リズムに及ぼす影響(体液・内分泌,一般口演,第60回 日本体力医学会大会), 鷹股 亮; 川本 麻理子; 森本 恵子, 2005年12月01日, 54, 6, 512, 512
  • 日本語, 長崎大学熱帯医学研究所共同研究報告集, 長崎大学, 血液浸透圧と体温調節反応:汗ナトリウム濃度との関連, 鷹股 亮; 森本 武利, 1998年07月, 9, 118, 118
  • 日本語, 体力科學, 日本体力医学会, 160. 静的運動時の骨格筋血流調節における性差、性周期の影響(呼吸・循環, 第61回 日本体力医学会大会), 鷹股 亮; 川本 麻理子; 森本 恵子, 2006年12月01日, 55, 6, 658, 658

書籍等出版物

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  • ニュー運動生理学, 真興交易(株)医書出版部, 2015年, その他, 査読無し, その他
  • からだと温度の事典 脱水時の体温調節, 朝倉書店, 2010年, その他, 査読無し, その他
  • からだと温度の事典 運動時の体液調節, 朝倉書店, 2010年, その他, 査読無し, その他
  • 運動生理学のニューエビデンス, 真興交易社, 2010年, その他, 査読無し, その他
  • 身体トレーニング 運動生理学からみた身体機能の維持・向上 運動時の体液変化とその循環・体温調節への影響, 真興交易(株)医書出版部, 2009年, その他, 査読無し, その他
  • 環境生理学, 北海道大学出版会, 2007年, その他, 査読無し, その他
  • Environmental Physiology, 2007年, その他, 査読無し, その他
  • 人間の許容限界事典 14.体液, 朝倉書店, 2005年, その他, 査読無し, その他
  • 人間の許容限界事典 15.浸透圧, 朝倉書店, 2005年, その他, 査読無し, その他
  • 体温―運動時の体温調節システムとそれを修飾する因子― 体温調節システムと浸透圧調節, ナップ, 2002年, その他, 査読無し, その他
  • 最新栄養学第8版―専門領域の最新情報ー Chapter 11 水分・電解質バランスー体温調節および高温環境下での身体運動に及ぼす影響, 2002年, その他, 査読無し, その他
  • Merits of diluted sweat with training on arterial pressure and body temperature regulation in heat stress. In: Thermotherapy for Neoplasia, Inflammation, and Pain., Springer-Verlag, Tokyo, 2001年, その他, 査読無し, その他
  • 運動とホルモン 体液調節と液性因子, ナップ, 2001年, その他, 査読無し, その他
  • 新運動生理学(下巻) 環境と体液, 真興交易, 2001年, その他, 査読無し, その他
  • Merits of diluted sweat with training on arterial pressure and body temperature regulation in heat stress. In: Thermotherapy for Neoplasia, Inflammation, and Pain., Springer-Verlag, Tokyo, 2001年, その他, 査読無し, その他
  • Interrelationship between osmoregulation and thermoregulation in a hot engvironment and during exercise. In: Exercise, Nutrition, and Environmental Stress., Cooper Publishing Group, LLC, Camel, IN, 2000年, その他, 査読無し, その他
  • Interrelationship between osmoregulation and thermoregulation in a hot engvironment and during exercise. In: Exercise, Nutrition, and Environmental Stress., Cooper Publishing Group, LLC, Camel, IN, 2000年, その他, 査読無し, その他
  • スポーツ医科学 運動・スポーツと体内における反応 体液・血液の働き, 杏林書院, 1999年, その他, 査読無し, その他
  • Body fluid osmolality, blood volume and thermoregulation. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • The role of plasma osmolality in exercise-induced inhibition of cutaneous vasodilation. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • Effects of hypovolemia and hyperosmolality on cardiovascular responses to heat in awake rats.. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • Near infrared spectrophotometric monitoring of rhythmic fluctuation in oxygenated hemoglobin and myoglobin during muscular exercise. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • Body fluid osmolality, blood volume and thermoregulation. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • The role of plasma osmolality in exercise-induced inhibition of cutaneous vasodilation. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • Effects of hypovolemia and hyperosmolality on cardiovascular responses to heat in awake rats.. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • Near infrared spectrophotometric monitoring of rhythmic fluctuation in oxygenated hemoglobin and myoglobin during muscular exercise. In: The 1997 Nagano Symposium on Sports Sciences., Cooper Publishing Group, LLC, Carmel, IN, 1998年, その他, 査読無し, その他
  • Osmotic inhibition of thermally induced cutatneous vasodilation in humans and its role in the inhibition of cutaneous vasodilation during exercise. In: Thermal Physiology 1997. Proceedings of the International Symposium on Thermal Physiology., The August Krogh Institute, Copenhagen, 1997年, その他, 査読無し, その他
  • Osmotic inhibition of thermally induced cutatneous vasodilation in humans and its role in the inhibition of cutaneous vasodilation during exercise. In: Thermal Physiology 1997. Proceedings of the International Symposium on Thermal Physiology., The August Krogh Institute, Copenhagen, 1997年, その他, 査読無し, その他
  • Central venous pressure and cardiovascular responses to hyperthermia. In Temperature Regulation: Advances in Pharmacological Sciences, Birk-hauser Verlag, Basel, 1996年, その他, 査読無し, その他
  • Cardiovascular response to exercise in a hot environment. In Physiological Basis of Occupational Health: Stressful Environment. Progress in Biometeorology vol. 11., SPB Academic Publishing bv, Amsterdam, The Netherlands, 1996年, その他, 査読無し, その他
  • Central venous pressure and cardiovascular responses to hyperthermia. In Temperature Regulation: Advances in Pharmacological Sciences, Birk-hauser Verlag, Basel, 1996年, その他, 査読無し, その他
  • Cardiovascular response to exercise in a hot environment. In Physiological Basis of Occupational Health: Stressful Environment. Progress in Biometeorology vol. 11., SPB Academic Publishing bv, Amsterdam, The Netherlands, 1996年, その他, 査読無し, その他
  • Central venous pressure and cardiovascular responses to hyperthermia. In Temperature Regulation: Advances in Pharmacological Sciences, Birk-hauser Verlag, Basel, 1994年, その他, 査読無し, その他
  • Central venous pressure and cardiovascular responses to hyperthermia. In Temperature Regulation: Advances in Pharmacological Sciences, Birk-hauser Verlag, Basel, 1994年, その他, 査読無し, その他
  • Thirst, Exercise and Thermoregulation: Interrelationships. In Perspective in Exercise Science and Sports Medicine Volume 6, Exercise, Heat and Thermoregulation, Benchmark Press, Carmel, IN, 1993年, その他, 査読無し, その他
  • Thirst, Exercise and Thermoregulation: Interrelationships. In Perspective in Exercise Science and Sports Medicine Volume 6, Exercise, Heat and Thermoregulation, Benchmark Press, Carmel, IN, 1993年, その他, 査読無し, その他
  • Effect of heat load on body fluid and circulation. In: Hyperthermic Oncology in Japan '91, Shinohara, 1992年, その他, 査読無し, その他
  • Effect of heat load on body fluid and circulation. In: Hyperthermic Oncology in Japan '91, Shinohara, 1992年, その他, 査読無し, その他
  • 体温の「なぜ?」がわかる生理学 〜からだで感じる・考える・理解する〜, 杏林書院, 26 脱水症と体温の密接な関係とは, 2021年04月, その他, その他
  • 解剖生理学 : 人体の構造と機能, 講談社, 河田, 光博; 三木, 健寿; 鷹股, 亮, 2020年01月, ix, 179p, 日本語, その他, 9784065166352, cinii_books

講演・口頭発表等

  • 森ゆめ, 国内, 第59回日本生気象学会大会, エストロゲンと暑熱環境曝露が摂食行動および体温調節機構に及ぼす影響, 口頭発表(一般), 2020年11月28日, 2020年11月29日, 日本語
  • 鷹股 亮, 国内, 第59回日本生気象学会大会, 摂食行動、睡眠覚醒リズム、うつ様行動に及ぼすエストロゲンと光環境の影響, シンポジウム・ワークショップパネル(指名), 2020年11月28日, 2201年12月, 日本語

Works(作品等)

  • 自律神経系中枢のMRIによる研究, 2005年, 2005年
  • マンガン造影を用いた、容量刺激、血圧変化に対する延髄および視床下部神経活動の解析, 2004年, 2004年
  • マンガン造影による浸透圧、容量刺激に対する視床下部神経核活動の解析, 2003年, 2003年
  • 経口補液飲料のナトリウム濃度が温熱脱水からの体液量回復に及ぼす影響, 2002年02月, 2002年03月
  • マイクロイメージング法による脳室周囲器官群および関連する視床下部・延髄の研究, 2002年, 2002年
  • T1緩和時間MRI法によるラット脳室周囲器官の測定, 2001年, 2001年

受賞

  • 久野寧記念賞, 1999年, 日本国

共同研究・競争的資金等の研究課題

  • 基盤研究(C), 2020年04月01日, 2023年03月31日, 20K11604, エストロゲンによる快楽性糖摂取行動促進作用のメカニズムと恒常性摂食調節との連関, 鷹股 亮; 森本 恵子, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4290000, 3300000, 990000
  • 基盤研究(C), 2018年04月01日, 2021年03月31日, 18K10991, 女性のライフステージによる女性ホルモン変動が脂質嗜好性に及ぼす影響とその作用機序, 森本 恵子; 鷹股 亮; 内田 有希, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4290000, 3300000, 990000, 2019年度は、若年女性9名と若年男性11名を対象として、口腔内脂肪酸感受性・脂質嗜好性・脂質摂取量を測定し、唾液の口腔由来細胞の脂肪酸受容体mRNA発現について検討した。2018年度と2019年度を合わせた若年女性20名と男性24名の測定結果について、性差や女性の月経周期性変化を評価した。一方、動物実験では、雌性ラットにおけるエストラジオ―ル(E2)の脂質摂取量への作用だけでなく、プロゲステロン(Pro)の作用およびE2とProの併用が脂質摂取量に与える影響についても検討を加えた。また、慢性の社会的心理ストレス(chronic psychosocial stress:CPS)下での雌性ラットの摂食及び体重変化にE2が影響を与える可能性について検討を開始した。 (1)口腔内オレイン酸感受性に性差はないことが確認された。また、若年女性では排卵前期にオレイン酸感受性が高いという月経周期依存性変化があることが判明した。一方、脂肪嗜好性には月経周期性変化は見られず、オレイン酸感受性との間にも明確な関連は認められなかった。しかし、舌への脂肪刺激後にはオレイン酸感受性と脂肪嗜好性との間に相関関係が見られた。なお、血漿エストロゲン・プロゲステロン濃度と脂肪嗜好性との関には相関関係は認められなかった。 (2)閉経モデルである卵巣摘出(OVX)ラットへのPro補充は経時的な高脂肪食摂取量や体重増加量に影響を与えなかった。一方、絶食後の高脂肪食摂取量はE2補充群では抑制されたが、Pro補充群やE2・Pro併用補充群では抑制されなかった。したがって、Proは長期の摂食調節には関与しないものの、短期的にはE2の摂食抑制作用を阻害する可能性が示唆された。また、OVXラットにおけるCPS下のエネルギー摂取量および体重増加量の減少をE2補充は抑制するとの結果を得た。
  • 基盤研究(B), 2016年04月01日, 2020年03月31日, 16H03026, 光・温度環境が閉経後女性の心身の健康に与える影響とそのメカニズムの解明, 鷹股 亮; 森本 恵子; 杉本 直俊, 日本学術振興会, 科学研究費助成事業 基盤研究(B), 奈良女子大学, 17420000, 13400000, 4020000, エストロゲン欠乏は、過食・肥満、うつ様行動の増加を惹き起こしたが、これはエストロゲン欠乏により光感受性が減弱し、生体リズム調節の機能が弱まることによることが示された。エストロゲンが欠乏しても、明期に強い光への曝露や摂食パターンを調整することにより、これら症状の少なくとも一部は改善された。 また、エストロゲン欠乏による過食・肥満、うつ様行動の増加にはセロトニン神経系の機能の低下が原因である可能性が示され、抗うつ剤であるフルオキセチンはこれらの健康障害を改善する可能性が示された。, url
  • 挑戦的萌芽研究, 2015年04月01日, 2017年03月31日, 15K12355, 光環境と摂食行動のリズムパターンの制御による閉経後女性の肥満予防法の開発, 鷹股 亮, 日本学術振興会, 科学研究費助成事業 挑戦的萌芽研究, 奈良女子大学, 3640000, 2800000, 840000, エストロゲン(E2)欠乏による過食・肥満は、摂食行動リズムの乱れを伴う。またE2が光依存性に摂食量を調節している可能性を我々は示してきた。本研究では、E2欠乏による過食・肥満が光環境と摂食行動リズムの調節により抑制できるかを検討した。 E2欠乏は光刺激による摂食・肥満抑制作用を減弱させる可能性が示された。さらに、強い光刺激曝露は、E2欠乏状態でも摂食量、体重増加を抑制した。また、強制的な摂食行動のリズム形成は、E2欠乏状態でも過食・肥満を抑制した。以上、生活環境である光環境の制御と摂食リズムを考慮した適切な生活習慣により、閉経後女性の過食・肥満を抑制できる可能性が示された。, url
  • 基盤研究(C), 2014年04月01日, 2017年03月31日, 26350118, メタボリックシンドロームにおける機能性食品のインクレチン分泌促進効果の検討, 根岸 裕子; 鷹股 亮; 山形 一雄; 池田 克巳, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 武庫川女子大学, 4810000, 3700000, 1110000, 本研究より、メタボリックシンドローム関連疾患発症・進展にインクレチンが関与している可能性を示す結果が得られた。GLP-1だけではなく、GLP-1を介さないDPP-4によるメタボリックシンドローム関連疾患への関与が示唆された。さらに、酒粕などの食品・植物由来成分について、メタボリックシンドローム関連疾患の進展抑制を有する食品・植物由来成分が明らかとなり、そのうちインクレチンを介した作用を有する物質が明らかとなった。 今後、メタボリックシンドローム関連疾患に対し、GLP-1だけではなく、DPP-4阻害作用にも注目し、ヒトへの有効な機能性食品探索を実施することが重要であると考えられた。, url
  • 基盤研究(C), 2012年04月01日, 2015年03月31日, 24500975, エストロゲンによる摂食抑制と摂食行動日内リズム調節の関連の機序解明, 鷹股 亮, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 5200000, 4000000, 1200000, エストロゲンは、ラットにおいて明期に特異的に摂食を抑制する。本研究では、エストロゲンの明期に特異的な摂食抑制作用は、光に対する反応性の亢進を伴っており、光依存性であることが明らかになった。また、エストロゲンは糖利用低下に対する摂食行動とORX-Aニューロンの活性化を明期に特異的に抑制し、エストロゲンによる糖利用低下時のORX-Aニューロン活動の抑制にセロトニンが関与している事が示された。従って、エストロゲンの摂食抑制作用は、光依存性であり、脳内セロトニンが重要な役割を果たしている可能性が示された。, url
  • 基盤研究(B), 2011年04月01日, 2014年03月31日, 23300275, 女性の精神性ストレス緩和のための機能性食品の研究, 森本 恵子; 小城 勝相; 鷹股 亮; 根岸 裕子; 吉田 謙一; 矢野 重信, 日本学術振興会, 科学研究費助成事業 基盤研究(B), 奈良女子大学, 17940000, 13800000, 4140000, 精神性ストレスおよび閉経は心血管疾患の危険因子である。我々の先行研究では雌性ラットにおいてエストロゲンが精神性ストレスによる循環反応を緩和した。本研究ではエストロゲンのストレス緩和作用のメカニズムの解明とその代替としての抗酸化ビタミンやイソフラボンの作用を検討した。 その結果、エストロゲンはレニン-アンギオテンシン系の制御によりストレス性昇圧反応を抑制した。しかし、閉経モデルラットへの葛蔓抽出物投与はストレス性昇圧反応を抑制しなかった。 一方、閉経後女性は同年代の閉経前女性と比べ、安静時の血管内皮機能が低下し、ストレス時の血管抵抗が増大したが、ビタミンC経口投与により改善されることが判明した。, url
  • 基盤研究(C), 2008年, 2010年, 20590230, エストロゲンの酸化ストレス軽減による精神性ストレス時の血圧調節メカニズムの解明, 森本 恵子; 鷹股 亮; 上山 敬司; 木村 博子; 吉田 謙一, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4940000, 3800000, 1140000, 健康な若年男女および閉経前・後の中年女性を対象とした実験より、エストロゲンが減少する閉経後には、マイルドな精神性ストレス時に前腕血管抵抗が増大するが、これには酸化ストレスが関与することが示唆された。また、閉経モデルラットを用いた実験では、精神性ストレス時の循環反応に対するエストロゲン補充の抑制作用には、すくなくとも一部に、酸化ストレス軽減を介した作用が関与することを明らかにした。, url
  • 基盤研究(C), 2005年, 2006年, 17590202, 精神的ストレス時の血圧調節に及ぼすエストロゲンの作用メカニズム, 森本 恵子; 鷹股 亮; 上山 敬司; 木村 博子; 吉田 謙一, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 3600000, 3600000, 1.マイルドな精神的ストレスであるケージ交換ストレス(CS)による血漿ノルエピネフリン(NE)増加反応は、雄ラットにのみ見られるという性差が存在し、これは昇圧反応の性差の原因と考えられる。このメカニズムとして、雄では一酸化窒素(NO)がNE増加を促進させることが示唆された。 2.卵巣摘出ラットでもCSストレスによるNE増加反応が見られるが、エストロゲン補充により抑制される傾向があった。また、エストロゲン補充により安静時の血漿NO代謝産物(NOx)が増加する傾向があり、逆に、酸化ストレスマーカーである4-hydroxy-2-nonenalは低下した。 3.エストロゲンの中枢神経系を介したストレス反応を緩和するメカニズムについて検討した。c-Fosタンパク質を神経細胞活性化の指標とし、各脳部位におけるCSストレスの影響とそれに対するエストロゲン補充の効果を免疫組織化学法を用いて測定した。その結果、CSストレスにより卵巣摘出ラットでは、外側中隔核、視床室傍核、弓状核、視床下部室傍核(PVN)、視床下部背内側核(DMD)、青斑核(LC)でc-Fos発現が有意に増加したが、正常雌では増加は見られなかった。しかし、卵巣摘出後にエストロゲン補充を行なうとPVN、DMD、LCではc-Fosの増加が抑制された。さらに、LCではストレスによるカテコラミン産生細胞の活性化が、エストロゲン補充により有意に抑制されることが判明した。同部位では、エストロゲン受容体αの存在が免疫染色で確認でき、エストロゲンの直接作用の可能性が示唆された。また、PVN小細胞領域では、エストロゲン補充はNO産生ニューロンのストレスによる活性化を促進することを見いだした。これはエストロゲンの抑制作用におけるNOを介したメカニズムを示唆している。 以上の結果より、エストロゲンは末梢血管系においては酸化ストレス抑制作用によって、中枢神経系ではPVN、DMD及びLCの神経細胞に対する抑制作用によって、ストレス反応を緩和する可能性が示唆された。
  • 基盤研究(C), 2004年, 2005年, 16590174, エストロゲンが摂食・飲水行動に及ぼす影響とその脳内機構の解明, 鷹股 亮; 森本 恵子, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 3700000, 3700000, エストロゲンが摂食行動と浸透圧調節機能に及ぼす影響とそのメカニズムを明らかにすることを目的とした。7週齢の雌ラットの卵巣を摘出し、エストロゲン補充(E2)群とプラセボ補充(Pla)群に分けた。Pla群では、E2群に比べ摂食量が増加し、弓状核におけるc-Fos発現が有意に多かった。Pla群では、明期の摂食量の割合がE2群に比べて有意に大きくなった。視交差上核の明期のc-Fos発現は、Pla群ではE2群に比べて有意に少なく、明期と暗期のc-Fos発現量の差が小さくなった。これらより、エストロゲンが直接または間接的に視交差上核に作用し摂食パターンを変化させている可能性が示唆された。48時間絶食後の摂食量および弓状核におけるc-Fos発現の増加に両群間の差は認められなかった。エストロゲンは絶食により誘導される摂食行動には影響を及ぼさないが、自発的摂食行動に影響することが示された。次に浸透圧調節に及ぼすエストロゲンの影響を検討した。E2群とPla群で浸透圧刺激(1.5M NaCl;3.3ml/kg)に対する飲水量を比較すると、E2群でPla群に比べて有意に少なかった。中枢における浸透圧調節関連部位のc-Fos発現は、終板器官(OVLT)、室傍核(PVN)視索上核(SON)においてE2群の方が少なかった。また、PVN、SONのバゾプレッシン陽性ニューロンにおけるc-Fos発現の割合はE2群で有意に低かった。脳室内アンギオテンシンII投与に対する飲水量もE2群でPla群よりも少なく、OVLT、脳弓下器官(SFO)、正中視索前核(MnPO)およびPVN、SONにおけるc-Fos発現量が少なかった。SONのバゾプレッシン陽性ニューロンにおけるc-Fos発現の割合はE2群で有意に低かった。エストロゲンは浸透圧刺激性の飲水およびバソプレッシン分泌反応を抑制し、この浸透圧調節反応の抑制は、少なくとも一部は脳内アンギオテンシンIIに対する反応性の低下を介するものであると推察される。
  • 基盤研究(C), 2003年, 2004年, 15590208, 精神性ストレス時の血圧調節におけるエストロゲンの効果とその分子機構, 森本 恵子; 鷹股 亮; 吉田 謙一, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 3600000, 3600000, 本研究では、エストロゲンが精神性ストレス負荷時の昇圧反応に及ぼす効果とそのメカニズムについて下記のような成果を得た。 (1)エスロゲンは一窒素(NO)を介してラットのストレス性昇圧反応を抑制する。 テレメトリーシステムを用いて、成熟ラットのケージ交換ストレス負荷による昇圧反応を比較すると、オス(M)群に比べメス(F)群では減弱する傾向が認められた。また、卵巣摘出後プラセボ補充(P)群に比べ、卵巣摘出後エストロゲン補充(E)群ではケージ交換および拘束ストレスによる昇圧反応が有意に抑制された。また、一酸化窒素合成酵素(NOS)阻害剤の前投与により、ケージ交換ストレス時の昇圧反応におけるP群とE群の間の差は消失した。さらに、腸間膜の内皮型NOS (eNOS)発現量はE群ではM群、P群に比べ有意な増加を示した。以上の結果より、ラットにおいてエストロゲンはストレス時の血圧上昇反応を減弱させるとともに、末梢血管におけるeNOSの発現量を増加させることが判明した。この発現量の増加がストレス時に血管壁におけるNO産生を増大させ、末梢血管抵抗の増加を緩和している可能性が示唆された。 (2)ヒトにおいて精神性ストレス時の昇圧反応をエストロゲンレベルによって変化する。 若年女性の安静時血圧には月経(M)期と排卵前(O)期の間で有意な差はなかったが、血漿norepinephrine (NE)濃度は、O期で有意に高かった。Color Word Test (CWT)による収縮期・拡張期血圧増加反応及びNE増加反応は、M期に比べO期で減弱する傾向があった。閉経後女性では、若年女性に比べ、安静時の拡張期血圧が有意に高く、CWT負荷による拡張期血圧の増加反応が有意に増大しており、安静レベルまで回復するのに時間を要した。以上の結果より、ヒトにおいてもエストロゲンは精神性ストレス負荷による昇圧反応を減弱させる可能性が示唆された。
  • 基盤研究(C), 2002年, 2003年, 14570064, 体温調節系に及ぼす体液浸透圧調節系と容量調節系の相互作用, 鷹股 亮; 森本 恵子, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 3500000, 3500000, 体温調節系の反応に対する体液調節系からの影響、特に浸透圧刺激と容量刺激の相互作用が体温調節反応の及ぼす影響を明らかにするために主にヒトを対象とした実験を行なった。さらに、体液調節系機能のメカニズムを明らかにするために、ラットを用いた基礎的な実験も行なった。これらの実験より、以下のことが明らかになった。 体温低下時の体温調節反応である、熱産性量の増加反応と末梢血管収縮反応は、ともに圧受容器からの入力により修飾されることをヒトを対象とした実験で明らかにした。 温熱負荷時には、血漿浸透圧上昇により、容量調節性末梢血管収縮反応が亢進することを明らかにした。この亢進は通常体温時には、認められないことより、血漿浸透圧上昇は血管収縮性神経の活動を亢進させるのではなく、血管拡張反応を抑制している可能性を示した。また、血漿浸透圧上昇による皮膚血管拡張反応の抑制は、能動的血管拡張反応の抑制であることを、ブロッカーを用いた実験より明らかにした。 浸透圧受容部位と考えられている、脳弓下器官の毛細血管水透過性をMRJを用いてin vivoで定量化した。この部位の毛細血管の水透過性は、脳における毛細血管の値としては極めて高く、BBBが存在する皮質における透過性の10-100倍大きいことが明らかになった。この結果は、SFOが血漿(BBBの外側)の浸透圧を受容する部位として機能するに極めて効果的な構造をしていることを示唆する。また、MRIを用いてin vivoで浸透圧刺激時の脳内の活性化部位を同定した。同定された活性化部位は、c-Fosを用いて免疫組織化学的に検出された部位とほぼ同様であることから、この方法の有用性が検証された。
  • 基盤研究(C), 2002年, 2003年, 14571683, 環境が涙液動態に及ぼす影響の人工気候室を用いた基礎研究, 横井 則彦; 鷹股 亮, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 京都府立医科大学, 3500000, 3500000, ソフトコンタクトレンズ(SCL)上の涙液は薄く、SCL装着眼では、レンズ表面から涙液の蒸発が亢進して、ドライアイ症状を訴える。また、経験的に、このドライアイ症状は、外部環境の影響を受けることが知られる。そこで、人工気候室を用いて各種の環境条件を作り、SCL上の涙液動態やSCL装用眼の乾燥感の有無を調べ、環境が涙液に与える影響について検討した。検討項目は、1)季節的な温度、湿度の影響、2)温度、湿度の個々の影響、3)SCL厚みと含水率の影響、4)風の影響である。1)季節的な温度、湿度の影響では、環境(1)温度:15℃;湿度:20%、環境(2)25℃;40%、環境(3)35℃;50%の3つの異なる環境と作り、2)温度、湿度の個々の影響では、湿度(水蒸気圧)を一定(9.51mmHg)とし、温度を(1)15、(2)25、(3)35℃と変化させた場合と、温度を一定(25℃)にし、湿度を(4)2.56、(5)9.51、(6)16.46mmHgと変化させた場合を作成した。3)SCLの厚みと含水率の影響の検討では、中心厚みを0.16mmとα0.05mmで、含水率を72.0%と37.5%で、15℃20%の環境下で装着させて検討した。4)風の影響では、25℃40%環境下で扇風機を用いて風速(1)0.0,(2)α5(ビル衛生管理法基準値).(3)1.0.(4)5.5(自転車走行時を想定)m/sの風をSCL装用眼に当てて検討した。評価方法としては、SCL装用時の涙液貯留量をビデオメニスコメトリー法で評価し、SCL上の涙液動態をDR-1^R(興和社製)による涙液の観察およびNon-invasive break up timeの測定によって評価し、乾燥感は問診してた。その結果、季節的な温度、湿度の影響では、低温、低湿の冬環境では、涙液は非薄化、不安定化し、乾燥感の程度が増加することが示された。次に、温度・湿度の個々の影響では、SCL上の涙液は低湿の影響を受けなかったが、低温になると、涙液は菲薄化、不安定化し、乾燥感の程度が増加することが示された。さらに、SCLの厚みと含水率の影響の検討では、SCL上の涙液は、レンズの厚みの影響は受けなかったが、高含水率SCLでは、低含水率より、涙液は菲薄化、不安定化し、乾燥感が増加した。風の影響では、風速の増加に伴って、SCL上の涙液は菲薄化、不安定化し、乾燥感が増加した。
  • 基盤研究(C), 2001年, 2002年, 13670047, T_1緩和時間MRI法を用いた脳室周囲器官群の水透過性の解析, 瀬尾 芳輝; 村上 政隆; 鷹股 亮; 伊藤 俊之, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 京都府立医科大学, 2900000, 2900000, 本研究は、脳室周囲器官群部位での血液脳関門(BBB)・脳脊髄液脳関門の水透過性を、明らかにすることを目的として実施した。 まず、NMRプローブ(高周波検出用コイル)を、ラット脳測定用に最適化し、高感度化・高均一度化した。測定パルスにAdiabatic pulseを導入することにより、視床下部・下垂体に至るまで高精度のT_1緩和時間測定を可能とした。正常のBBBを透過しない緩和試薬(Gd-DTPA)を血管内に連続投与し、血管内の水の緩和時間を短縮させた時、血管壁を介しての水の透過性が高ければ、水の交換により血管外組織の水T_1緩和時間は短縮される。Gd-DTPAを静注し、脳室周囲器官および脳実質各部位のT_1緩和速度を測定した。投与量を漸次増加していくと、BBBの堅固な皮質や視床では1/T1(0.7/s)は変化しなかったが、脳弓下器官(SFO)では1.5/sに増加し、1.5mmol/kg以上では一定値を示した。下垂体後葉やBBBの存在しない皮膚では、Gd-DTPA投与量に比例して1/T1が増加した(>10/s)。また、BBBを高張輸液により破壊した場合、脳実質やSFOでは1/T1の増加が認められたが、下垂体後葉や皮膚では変化しなかった。以上の結果より、正常なSFO毛細血管はGd-DTPAを透過せず、Gd-DTPA投与による1/T1の変化量(0.84/s)は、毛細血管を介しての水の交換速度を反映していると考えられる。毛細血管体積表面積比より、拡散透過係数は3.7x10-3cm/sとなった。この値は、腎直血管や筋毛細血管と同程度の値であり、BBBより10から100倍大きいことが明らかとなった。
  • 基盤研究(C), 2000年, 2001年, 12670065, バゾプレッシン分泌に及ぼすストレス反応系、体温調節系と浸透圧調節系の相互連関, 鷹股 亮; 伊藤 倫之; 伊藤 俊之, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 京都府立医科大学, 3200000, 3200000, われわれは、体温の上昇とストレスの複合刺激がバゾプレッシン分泌に及ぼす影響を明らかにするために、エンドトキシン血症および運動をこれら複合的刺激のモデルとして用い、それぞれラットおよびヒトを対象として実験を行った。 ラットにバクテリア内毒素であるLipopolysaccharide(LPS)を静脈内投与すると血漿浸透圧や血漿量の変化を伴わず、血漿パゾプレッシン濃度が上昇し、飲水行動が起こった。これらの反応は、あらかじめ脳室内にアンギオテンシンIIのAT1受容体アンタゴニストであるLosartanを投与すると、浸透圧上昇時のこれら反応を抑制するのと同様に、抑制することができた。したがって、LPS投与時のバゾプレッシン分泌は、LPSにより体液の状態に変化が起こり誘発されるのではなく、LPSの直接作用またはLPSによって誘発された何らかの物質により脳内アンギオテンシンIIのAT1受容体を介して起こる可能性が示唆された。運動時のバゾプレッシン分泌機構を明らかにするための実験をヒトを対象として行った。実験では、負荷漸増運動時の血漿浸透圧と血漿バゾプレッシン濃度の関係を求め、高張性食塩水輸液時のそれと比較した。運動強度が60%よりも低い低運動強度時には血漿浸透圧に対する血漿バゾプレッシン濃度は輸液時よりも低くかった。すなわち浸透圧性パゾプレッシン分泌は抑制された。一方運動強度が60%を超えると浸透圧上昇に対する血漿バゾプレッシン濃度の上昇が大きくなった。すなわち、浸透圧性バゾプレッシン分泌の亢進が起こった。血圧、心拍数は、運動強度に依存して上昇し、食道温、血漿乳酸濃度、血漿ACTH濃度は、運動強度が最大酸素摂取量60%を超えると急激な上昇を示した。低強度運動時の浸透圧性バゾプレッシン分泌の抑制は、主に血圧の上昇が原因であると考えられる。一方、高強度運動時の浸透圧性バゾプレッシン分泌の亢進は、ストレスによるCRH分泌、体温上昇が関与している可能性が示唆された。また、浸透圧刺激は、下垂体前葉からのACTH分泌には関わっていないことが明らかになった。
  • 奨励研究(A), 1998年, 1999年, 10770031, 浸透圧調節系の体温調節系・循環調節系に対する修飾機構の解析, 鷹股 亮, 日本学術振興会, 科学研究費助成事業 奨励研究(A), 京都府立医科大学, 1800000, 1800000, 1)ヒトにおいて、暑熱馴化により体液調節能が向上し、血漿浸透圧上昇による体温調節反応の抑制が減弱する。 温熱脱水(体重の約1.5-2.0%)後、被験者に水分の自由摂取を2時間にわたって行なわせた際の水分バランスをみると、暑熱馴化前では脱水量の約50%しか回復しないが、暑熱馴化(7日間)によりその回復は、約80%になり、暑熱馴化が体液調節機能を亢進させることが明らかになった。しかし、この体液調節機能の向上は、同様の暑熱馴化プログラムを行なった高齢者では認められなかった。従って、体液調節系と体温調節系の相互作用に加齢の影響があることが明らかになった。また、暑熱馴化は汗ナトリウム(Na)濃度を低下させることが知られている。汗Na濃度の低下は、発汗時の血漿浸透圧の上昇を増加させる。一方、我々は血漿浸透圧の上昇が体温上昇時の体温調節反応を抑制することを報告して来た。そこで、暑熱馴化が浸透圧上昇による体温調節機能の抑制作用が減弱させるのではないかという仮説を立て、実験を行った。その結果、浸透圧上昇に対する体温調節反応の抑制(発汗および皮膚血管拡張反応の深部体温閾値の上昇)は、汗Na濃度が低い被験者程小さくかった。従って、馴化している個人程浸透圧上昇による体温調節機能の抑制は小さくなることが明らかになった。 2)エンドトキシン血症時の飲水およびバゾプレッシン分泌に脳内アンギオテンシンIIが関与する エンドトキシン血症時には、体温上昇がおこるが血中のバゾプレッシン濃度の上昇および飲水行動が起こる。血漿浸透圧上昇時のバゾプレッシン分泌および飲水は脳内アンギオテンシンIIをブロックすることによって抑制できるが、LPS投与してエンドトキシン血症にしたラットにみられるバゾプレッシン分泌および飲水も脳内アンギオテンシンIIをブロックすることによって抑制できた。体温調節系と浸透圧調節系の相互作用に脳内アンギオテンシンが関与している可能性が示唆された。
  • 基盤研究(B), 1997年, 1998年, 09470017, 水分代謝から見た高齢者の暑熱適応能, 森本 武利; 八重樫 和宏; 鷹股 亮; 伊藤 俊之, 日本学術振興会, 科学研究費助成事業 基盤研究(B), 京都府立医科大学, 10700000, 10700000, 1. 高齢者における暑熱馴化と水分代謝の解析 高齢者9名青年男子6名を対象に8日間暑熱運動暴露を行い、実験の第1、8日に体温調節反応および水分代謝に関する測定を行った。その結果、高齢者では体液水分量の減少、腎濃縮能の低下による水分および塩分喪失量の増加、口渇感の低下による水分摂取量の減少、水分代謝関連ホルモンに対する反応性の低下、暑熱馴化不全が認められ、これらが高齢者の夏期における暑熱適応能の低下に関与すると考えられる(American Journal of Physiologyに投稿中)。 2. 熱中症の疫学 厚生省の死亡統計に基づいて、1968年から1994年にわたる27年間のわが国の熱中症死亡の現状を検討した。熱波を経験した年度には約150件の死亡が報告されているが、1994年度にはその数が589件に増加し、その64%が65歳以上の高齢者に認められた。今後地球温暖化が進めば、さらに増加する可能性を指摘し、総説として纏め、またInternational Journal of Biometeorology投稿中である。 3. 脱水と体温調節能の関係 脱水は体温調節能を低下させる。体温調節能に及ぼす脱水の影響について、われわれの教室で得た実験結果を、体液量変化の影響および浸透圧変化の影響に分け要約し、総説に纏めた。 4. 最大酸素摂取量と血液量の関係に対する年齢の影響 血液量と最大酸素摂取量の関係を、若年者および高齢者のそれぞれについて求めた。その結果、高齢者においても運動能は血液量の増加と平行して上昇したが、同一血液量において、高齢者では運動能は低値を示し、また若年群、高齢群とも女性で低値を示した。 以上の結果から、高齢者は暑熱に反復暴露しても水分代謝が高進せず、高齢者に於ける暑熱適応能低下の一因になっていると考えられる。
  • 奨励研究(A), 1996年, 1996年, 08770049, 浸透圧調節系に対する体温調節系からの修飾機構とその生理的意義のの解析, 鷹股 亮, 日本学術振興会, 科学研究費助成事業 奨励研究(A), 京都府立医科大学, 1000000, 1000000, 体温調節系と浸透圧調節系は密接に関連しあって機能している。我々はヒトにおいて体温の上昇が浸透圧調節系の機能を浸透圧依存性に亢進させることを明らかにしてきたが、ラットを用いた実験モデルを作成してそのメカニズムを更に明らかにすることを目的とした。 ラットを用いた実験モデルを作成するにあたって、先ずラットの浸透圧刺激性飲水パターンを明らかにするための実験を行った。ラットの側脳室内に高張性の人工髄液を持続注入して飲水量を測定した。また、容量刺激による飲水のパターンと浸透圧刺激性の飲水パターンを比較するため、利尿剤であるfurosemideを投与した際のラットの飲水量も測定した。浸透圧刺激は直ちに飲水を惹き起こしたのに対し、容量調節系の飲水の発現は、浸透圧刺激性の飲水に比べて有意に遅れ、更に長時間にわたって持続することが明らかとなった。この実験よりラットの飲水パターンは、イヌ等の動物と比べヒトのそれに近く、実験のモデル動物として妥当であることが明らかになった。しかし、ラットは、浸透圧刺激によりナトリウム利尿が起こって浸透圧調節に働く点はヒトとは異なる反応を示した。 体温上昇の浸透圧刺激飲水に対する影響を明らかにするためにラットに浸透圧刺激を加えた後の飲水量を高温環環境下(32℃)とラットにおける中性温度域である24℃の環境温下で比較した。室温32℃の環境下でラットの体温は、0.5℃から1℃上昇し、飲水量は体温の上昇により約30%低下した。この結果は、ヒトにおける反応とは異なった。体温の上昇によりラットの行動量が低下したことが飲水行動の抑制を惹き起こしたものと考えられる。現在、血漿バゾプレッシング濃度の測定を行っており、血漿バゾプレッシングの反応よりラットにおける体温上昇による飲水量の低下が、浸透圧調節系に対する抑制なのか行動の抑制であるのかが明らかになると期待される。また、ラットの体温の上昇を環境温の上昇にではなく、thermodeを用いて上昇させる実験も計画中である。
  • 一般研究(C), 1995年, 1995年, 07670091, 脳内浸透圧受容システムの暑熱脱水時血圧調節における生理的役割, 能勢 博; 鷹股 亮, 日本学術振興会, 科学研究費助成事業 一般研究(C), 信州大学, 2200000, 2200000, 発汗による血漿浸透圧の上昇は発汗と皮膚血管拡張の抑制を引き起こし熱放散を減少させる。温熱脱水時の脳脊髄液の浸透圧上昇が血圧調節に与える影響を検討する目的で、脱水したラットの側脳室内に低張性人口髄液を注入して側脳室内のNa濃度([Na]_)を脱水前の値に回復させた場合の動脈血圧および心拍出量を連続測定した。その結果、[Na]_の低下に比例して動脈血圧、心拍出量は低下した。これらの結果は温熱脱水による[Na]_の上昇は低血液量に起因する低血圧を防止する上で重要な入力信号であることを意味する。次に高[Na]_の高体温時の皮膚血管への影響を検討する目的で、ラットの側脳室内に高張性人口髄液を注入したときの平均動脈血圧(MAP)、中心静脈圧、尾動脈血流量(CBF)を連続測定した。尾動脈の血管コンダクタンス(CVC)はCBF/MAPで算出した。赤外線ランプによって食道温を37℃から40℃まで上昇させると、CBFは2.3±0.4ml/min(平均値±標準誤差,n=14)から3.2±0.4ml/minに上昇した(p<0.001)。一方、MAPは125±5mmHgから95±5mmHgに低下し(p<0.01)、CVCは0.019±0.003から0.034±0.004ml/(min mmHg)に上昇した。 MAPとCVCの間に高い逆相関関係が観察された(r=-0.94,p<0.001)。体温を40℃に上昇させたラットの側脳室内に高張性人口髄液を注入するとMAPおよびCVCは熱負荷の前の値にまで回復し、その際CVCとMAPの間に熱負荷と同様高い逆相関が観察され(r=-0.93,p<0.001)、回帰係数は熱負荷時とほぼ一致した。 以上の結果は体温上昇による尾部皮膚血管の拡張は末梢血管抵抗を低下させ動脈血圧の維持を困難にすること、さらに温熱脱水等による髄液浸透圧の上昇は高体温時の過度の皮膚血管拡張を抑制して血圧維持に働くことが明らかになった。
  • 奨励研究(A), 1995年, 1995年, 07770050, 高温環境下での蒸発性熱放散に対する脳室周囲器官浸透圧受容器からの修飾, 鷹股 亮, 日本学術振興会, 科学研究費助成事業 奨励研究(A), 京都府立医科大学, 1000000, 1000000, 脱水等による血漿浸透圧の上昇は,高温環境下での体温調節反応である発汗や蒸発性熱放散を抑制することが知られている。この浸透圧の体温調節反応抑制のメカニズムを明らかにすることを最終目的として実験を行った。 第一段階として浸透圧刺激が蒸発性熱放散を特異的に抑制するのか、それとも高温環境下での体温調節反応一般に抑制的に働くのかを明らかにすることを目的として、ヒトの皮膚血管拡張反応に対する血漿浸透圧上昇の影響を検討した。この実験ではさらに、血漿浸透圧上昇の皮膚血管拡張反応に対する影響を定量化するために、血漿浸透圧をいろいろ変化させて皮膚血管拡張がおこる閾値深部体温との関係を求めた。血漿浸透圧は,0.9%,2%,3%の食塩水を静脈内に輸液することによって変化させた。皮膚血管拡張開始の深部体温閾値は血漿浸透圧が上昇する程高温側にシフトし,その結果同じ温熱負荷にも関わらず浸透圧が高い程体温の上昇が大きくなった。この結果より、血漿浸透圧の上昇は、蒸発性熱放散のみならず皮膚血管拡張反応にも抑制作用があることが明らかとなった。即ち,浸透圧刺激が体温調節中枢に影響を及ぼしている可能性が示唆された。更に、その抑制の程度は血漿浸透圧が上昇するほど上昇することが明らかとなった。 現在ラットを用いた実験モデルを作成し実験を進行している。今後,浸透圧受容器から体温調節中枢に対する影響をラットのモデルでさらに明らかにしていく予定である。

Ⅲ.社会連携活動実績

1.公的団体の委員等(審議会、国家試験委員、他大学評価委員,科研費審査委員等)

  • 日本生気象学会, 理事, 2005年, 9999年, 日本生気象学会, 学協会
  • 日本生理学会, 評議員, 日本生理学会, 学協会


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