Prenatal exposure to ethanol potentiates morphine-induced hypothermia in adult rats.

We have shown that adult rats, exposed to ethanol in utero, are hypersensitive to the analgesic and pituitary-adrenal activating effects of morphine. In the present experiment, two other responses to morphine, hyperthermia and hypothermia, were examined. Compared to controls, adult rats prenatally exposed to ethanol showed a potentiated hypothermic response to 10 and 30 mg/kg morphine. Hyperthermia elicited by low doses of morphine (1.25-5.0 mg/kg) was not affected by prenatal exposure to ethanol. These results extend our observations suggesting that exposure to ethanol in utero produces long-lasting perturbations in opioid systems. That hyperthermia is not affected, however, indicates that these changes are apparently not ubiquitous.