5-HT1A受体阻断剂对乙醇引起大鼠低体温和行为性体温调节反应的影响

目的：观察5-羟色胺1A （5-HT_1A）受体阻断剂p-MPPI对乙醇引起大鼠低体温和行为性体温调节反应的影响。方法：用无线遥控测温技术记录成年雄性SD大鼠体核温度和活动的变化。用无线遥测温度梯度仪监测大鼠体核温度和行为性体温调节活动，将大鼠置于15℃~40℃的温度梯度箱内，并允许动物自由选择箱内温度，观察乙醇（3 g/kg）引起低体温和行为性体温调节的反应以及5-HT_1A受体阻断剂p-MPPI （1 mg/kg）对其效应的影响。结果：①乙醇能引起大鼠快速的体温降低反应，同时动物选择较低的环境温度。②5-HT_1A受体阻断剂p-MPPI能明显阻断乙醇引起的低体温和行为性体温调节变化。结论：①乙醇能使体温调定点降低，因为乙醇引起低体温时，大鼠选择较冷环境温度区；②5-HT可能参与乙醇引起低体温与行为性体温调节活动。

Effects of 5-HT1A receptor antagonist on ethanol induced hypothermia and behavioral thermoregulatory response in rats

Objective: To observe the effects of 5-HT_1Areceptor antagonist p-MPI on ethanol induced hypothermia and behavioral ther-moregulatory response in rats.Methods: Core temperature and motor activities were monitored in undisturbed male SD rats using radioteleme-try. The behavioral thermoregulatory response and core temperature were monitored in rats using radiotelemetric temperature gradient apparatus. The rats were placed in a temperature gradient that permitted the selection of ambient temperature ranging from 15℃ to 40℃. Effect of ethanol (3 g/kg) and 5-HT_1A receptor antagonist p-MPPI(1 mg/kg) on core temperature, motor activities, and the behavioral thermoregulatory re-sponse were observed in rats.Results: ①Ethanol led to a rapid reduction in core temperature. The hypothermic responses were accompanied with a preference for cooler ambient temperature. ②5-HT_1A receptor antagonist attenuated the hypothermia induced by ethanol, and accompa-nied with a selection for warmer ambient temperature.Conclusion: ①Behavioral thermoregulatory observations suggested that the ethanol could decrease the thermoregulatory set point,because rats treated with ethanol selected cooler ambient temperature facilitates the reduction in core temperature.②5-HT might be involved in ethanol-induced hypothermia and behavioral thermoregulatory response.