Uchida Y, Nomoto T
Department of Pharmacology, Tokyo Women's Medical College, Japan.
Eur J Pharmacol. 1988 May 10;149(3):257-65. doi: 10.1016/0014-2999(88)90656-5.
The effects of thyrotropin-releasing hormone (TRH) administered via the lateral ventricle on the blood flow to the interscapular brown adipose tissue (IBAT) was studied in urethane anaesthetized rats. TRH in i.c.v. doses of 50 or 5 micrograms/kg produced a significant and transient decrease in IBAT blood flow. The effect of 5 micrograms/kg TRH was blocked by bilateral surgical denervation. TRH caused a comparable decrease in blood flow to both the innervated pad of unilaterally denervated rats and the intact pads of non-operated rats whereas no response to TRH was observed in the denervated pad. Adrenal demedullation partly inhibited but did not completely abolish the effect of TRH on IBAT blood flow and lessened the increase in serum adrenaline caused by TRH. The effect of TRH was dose dependently suppressed by pretreatment with prazosin 15 min prior to TRH. Yohimbine did not influence the effect of TRH on IBAT blood flow. Central administration of TRH affects the regional blood flow to IBAT and appears to interfere with neural mechanisms that involve mediation by the alpha 1-adrenoceptors on the vasculature. The effect is in part due to circulating adrenaline from the adrenal medulla.
在氨基甲酸乙酯麻醉的大鼠中，研究了经侧脑室注射促甲状腺激素释放激素（TRH）对肩胛间棕色脂肪组织（IBAT）血流量的影响。脑室内注射剂量为50或5微克/千克的TRH可使IBAT血流量显著且短暂减少。5微克/千克TRH的作用可被双侧手术去神经支配所阻断。TRH使单侧去神经大鼠的受神经支配垫以及未手术大鼠的完整垫的血流量出现类似程度的减少，而去神经支配垫对TRH无反应。肾上腺髓质切除部分抑制但未完全消除TRH对IBAT血流量的影响，并减轻了TRH引起的血清肾上腺素升高。在注射TRH前15分钟用哌唑嗪预处理可剂量依赖性地抑制TRH的作用。育亨宾不影响TRH对IBAT血流量的作用。中枢给予TRH会影响IBAT的局部血流量，并且似乎干扰了涉及血管系统上α1 -肾上腺素能受体介导的神经机制。这种作用部分归因于来自肾上腺髓质的循环肾上腺素。
