Chemical stimulation of the dorsomedial hypothalamus evokes non-shivering thermogenesis in anesthetized rats
Chemical stimulation of the dorsomedial hypothalamus evokes non-shivering thermogenesis in anesthetized rats
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DOI：
10.1016/s0006-8993(01)03369-8
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发表时间：
2002-02-22
期刊：
影响因子：
2.9
通讯作者：
DiMicco, JA
中科院分区：
文献类型：
--
作者：
Zaretskaia, MV;Zaretsky, DV;DiMicco, JA
微量注射GABA(A)受体拮抗剂双丘碱甲碘胺（BMI）对下丘脑背内侧（DMH）神经元的去抑制作用引发一系列自主神经和内分泌变化，类似于在情绪应激实验范式中看到的变化。老鼠的压力也会引起体温升高，部分原因是交感神经介导的棕色脂肪激活。本研究旨在探讨BMI微注射入DMH对大鼠核心体温和棕色脂肪温度的影响。在麻醉后的制备中，向DMH和毗邻的下丘脑后端微注射BMI 10 pmol/50 nl，可引起肩膜间棕色脂肪组织（IBAT）温度的显著和快速升高，以及较小程度的延迟性直肠温度升高，类似注射到室旁核或下丘脑腹内侧对这两项参数均无影响。IBAT的峰值升高与伴随这些变化的核心温度峰值升高和最大心率升高显著相关，并且通过1 mg/kg的普萘洛尔全身治疗消除了所有这些影响。在有意识的大鼠遥测仪器中，向DMH中微量注射BMI 10 pmol/100 nl可引起核心温度、心率、运动活动和血浆ACTH的显著升高。核心温度的升高与麻醉制剂中所见的延迟时间过程相似。这些结果表明，DMH神经元的激活引起体温升高，这在很大程度上是由于交感神经肾上腺介导的棕色脂肪的激活。(C) 2002年Elsevier Science B.V.出版
Disinhibition of neurons in the dorsomedial hypothalamus (DMH) by microinjection of the GABA(A) receptor antagonist bicuculline methiodide (BMI) elicits a range of autonomic and endocrine changes resembling those seen in experimental paradigms for emotional stress. Stress in rats is also known to provoke increases in body temperature resulting in part from sympathetically mediated activation of brown fat. The purpose of the present study was to examine the effect of microinjection of BMI into the DMH on core body temperature and temperature of brown fat in rats. In anesthetized preparations, microinjection of BMI 10 pmol/50 nl into the DMH and adjoining posterior hypothalamus elicited marked and rapid increases in temperature in interscapular brown adipose tissue (IBAT) and lesser delayed elevations in rectal temperature, Similar injections into the paraventricular nucleus or ventromedial hypothalamus had no effect on either parameter. Peak increases in IBAT were significantly correlated with both peak increases in core temperature and maximal increases in heart rate that accompanied these changes, and all of these effects were abolished by systemic treatment with propranolol 1 mg/kg. In conscious rats instrumented for telemetry, microinjection of BMI 10 pmol/100 nl into the DMH evoked marked increases in core temperature as well as heart rate, locomotor activity, and plasma ACTH. The increase in core temperature occurred with a delayed time course similar to that seen in anesthetized preparations. These results indicate that activation of neurons in the DMH provokes increases in body temperature resulting in large part from sympathoadrenally-mediated activation of brown fat. (C) 2002 Published by Elsevier Science B.V.