Sex differences in thermoregulation after acute and chronic morphine administration in mice.

摘要

Sex differences in thermoregulation have been reported following acute morphine administration in rats only. This study assessed whether male and female mice also differ in thermoregulatory responses following acute and chronic morphine administration. Females displayed significantly higher baseline colorectal temperature and greater morphine (24mg/kg, s.c.) hypothermia (2. 5-fold) on day 1. Two additional days of morphine treatment did not alter baseline temperature readings on Day 4 in either sex, but significantly reduced the morphine hypothermia relative to Day 1 in a sex-dependent manner. Whereas the morphine hypothermia was completely abolished in males, significant hypothermia was still observed in females. Acute and chronic saline injections had no effect on colorectal temperature. The data demonstrate sex differences in the thermoregulatory responses to acute and chronic morphine administration in mice.