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

ABSTRACT

OBJECTIVE: To observe the effects of 5-HT1Areceptor 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-HT1A 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-HT1A receptor antagonist attenuated the hypothermia induced by ethanol, and accompa-nied with a selection for warmer ambient temperature. CONCLUSIONS: 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.