Heat loss and heat production induced by capsaicin.

辣椒素引起的热量损失和热量产生。

• 批准号: 08670096
• 负责人: OSAKA Toshimasa
• 金额: $ 1.34万
• 依托单位: National Institute of Health and Nutrition
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08670096/
• 关键词: 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

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.

皮下注射辣椒素 (5 mg/kg) 后，乌拉坦麻醉的大鼠尾部皮肤温度立即升高 2 小时，表明热量损失增加。注射辣椒素后，产热指标耗氧量也立即增加，并且这种增加持续了10多个小时。注射后1小时内结肠温度下降，随后出现长时间持续的高热期。肾上腺去髓质作用很大程度上减弱了辣椒素引起的产热，而肩胛间棕色脂肪组织（IBAT）的交感神经去神经作用则部分减弱了这一作用。然而，辣椒素引起的热量损失在这些大鼠中是正常的。在皮肤血管舒张最大化的大鼠中，辣椒素不会进一步增加热量损失，但会正常诱导热量产生。因此，辣椒素同时激活热量损失和热量产生的独立网络。接下来，我们检查了支配 IBAT 的辣椒素敏感感觉纤维的功能。将 IBAT 升温至 40-44°C 会减弱随后的 IBAT 去甲肾上腺素诱导的生热作用 (NIT)。在这个升温范围内，较高的 IBAT 温度会导致更多的 IBAT 产生。 衰减。施用 5.2 nmol CGRP（而非 P 物质或媒介盐水）模拟了 IBAT 热刺激的效果。施用辣椒素（1 mg/kg，皮下注射）也减弱了 NIT。IBAT 去神经或用辣椒素（一种辣椒素受体拮抗剂）预处理，可阻断辣椒素的作用。我们提出对温度和辣椒素敏感的神经纤维释放 CGRP 来减弱棕色脂肪细胞的 NIT。

项目成果

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)

Osaka, T.、Kobayashi, A.、Namba, Y.、Ezaki, O、Inoue, S.、Kimura, S. 和 Lee, T.H.：“棕色脂肪组织中的温度和辣椒素敏感神经纤维减弱了产热作用

T.Osaka et al.: "Temperature-and capsaicin-sensitive nerve fibers in brown adipose tissue attenuate thermogenesis in the rat" Pflugers Arch. 437. 36-42 (1998)

T.Osaka 等人：“棕色脂肪组织中的温度和辣椒素敏感神经纤维减弱了大鼠的生热作用”Pflugers Arch。