Heat loss and heat production induced by capsaicin.
| Project/Area Number |
08670096
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
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| Research Institution | National Institute of Health and Nutrition |
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Principal Investigator |
OSAKA Toshimasa National Institute of Health and Nutrition, Senior research Scientist, 老人健康・栄養部, 主任研究官 (30152101)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | Capsaicin / Body temperature regulation / Brown adipose tissue / calcitonin gene-related peptide / Set-point theory / セットポイント説 / 延髄腹外側部 / カテコラミン |
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| Research Abstract |
Subcutaneous administration of capsaicin (5 mg/kg) immediately increased the temperature of the tail skin for 2 h in urethan-anesthetized rats, suggesting an increase in heat loss. Oxygen consumption, an index of heat production, also immediately increased after the capsaicin injection, and this increase lasted for more than 10 h. Colonic temperature decreased within 1 h after the injection, and this decrease was followed by a long-lasting hyperthermic period. Adrenal demedullation largely attenuated the capsaicin-induced heat production, and sympathetic denervation of the interscapular brown adipose tissue (IBAT) partly did so. However, capsaicin-induced heat loss was normal in these rats. In rats with cutaneous vasodilatation maximized, capsaicin did not further increase heat loss but normally induced heat production. Thus, capsaicin simultaneously activates independent networks for heat loss and heat production.
Next, we examined the function of capsaicin-sensitive sensory fibers that innervate IBAT.Warming of the IBAT to 40-44ﾟC attenuated the subsequent noradrenaline-induced thermogenesis (NIT) of the IBAT.In this range of warming, higher IBAT temperatures resulted in more attenuation. Administration of 5.2 nmol CGRP but not substance P or vehicle saline mimicked the effect of thermal stimulation of IBAT.Administration of capsacin (1 mg/kg, s.c.) also attenuated the NIT.Denervation of the IBAT or pretreatment with capsazepine, a capsaicin receptor antagonist, blocked the effect of capsaicin. We propose that temperature- and capsaicin-sensitive nerve fibers release CGRP to attenuate the NIT of brown adipocytes.
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Report
(4 results)
Research Products
(9 results)
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[Publications] Kobayashi, A., Osaka, T., Namba, Y., Inoue, S., Lee, T.H., and Kimura, S.: "Capsaicin activates heat loss and heat production simultaneously and independently in rats." American Journal of Physiology. 275. R92-R98 (1998)
Description
「研究成果報告書概要(欧文)」より
Related Report
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[Publications] Osaka, T., Kobayashi, A., Namba, Y., Ezaki, O,Inoue, S., Kimura, S., and Lee, T.H.: "Temperature- and capsaicin-sensitive nerve fibers in brown adipose tissue attenuate thermogenesis in the rat." Pflugers Archiv. 437. 36-42 (1998)
Description
「研究成果報告書概要(欧文)」より
Related Report
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