Cui Y, Lee T F, Wang L C
Department of Zoology, University of Alberta, Edmonton, Canada.
Pharmacol Biochem Behav. 1993 Aug;45(4):935-9. doi: 10.1016/0091-3057(93)90143-h.
The present study investigated the change in thermoregulatory responses following microinjection of 5-hydroxytryptamine (5-HT) into the lateral septum and the hippocampus of unanesthetized, unrestrained rats. Intraseptal injection of 5-HT (5 to 20 micrograms) caused a dose-related fall in core temperature (Tb), which was associated with a decrease in heat production (HP). As the decrease in HP can not completely account for the magnitude of the decrease in Tb, increase in heat loss may also be involved in the 5-HT-induced hypothermia. In contrast to observed changes following intraseptal injection, no significant change in either Tb or HP was observed after microinjection of the same doses of 5-HT into the hippocampal areas, indicating that the hypothermic response to intraseptal injection of 5-HT is site specific. Further, the hypothermic response to intraseptal injection of 5-HT was only attenuated by systemic pretreatment with cyproheptadine, but not by naloxone or scopolamine, indicating that the hypothermic response is mediated by 5-HT receptor, but not by endogenous opioid and cholinergic systems.
本研究调查了在未麻醉、不受约束的大鼠的外侧隔区和海马体中微量注射5-羟色胺（5-HT）后体温调节反应的变化。向隔区内注射5-HT（5至20微克）会导致核心体温（Tb）呈剂量相关下降，这与产热（HP）减少有关。由于产热减少不能完全解释核心体温下降的幅度，散热增加可能也参与了5-HT诱导的体温过低。与隔区内注射后的观察变化相反，向海马区微量注射相同剂量的5-HT后，未观察到核心体温或产热有显著变化，这表明隔区内注射5-HT引起的体温过低反应具有部位特异性。此外，隔区内注射5-HT引起的体温过低反应仅被赛庚啶全身预处理减弱，而未被纳洛酮或东莨菪碱减弱，这表明体温过低反应是由5-HT受体介导的，而非内源性阿片类和胆碱能系统介导。
