Prenatal ethanol and ontogeny of pituitary-adrenal responses to ethanol and morphine.
The development of pituitary-adrenal activity was examined in the offspring of rat dams fed a 5.0% w/v ethanol-containing liquid diet or pair-fed an isocaloric diet, as a nutritional control, from day 8 of gestation to parturition. Serum corticosterone responses of the pups to challenges with ethanol (1.5 g/kg) or morphine (3.0 mg/kg) were determined at 5, 7, 10, 12 and 18 days of age. The pituitary-adrenal axis of normal neonates was activated by the drugs at each age, with a characteristic biphasic developmental pattern in which a trough occurred at day 7. The overall pattern was unaffected by prenatal ethanol exposure or pair-feeding. However, both prenatal treatments intensified the trough. Already on day 5 and also on day 7, corticosterone responses of both the ethanol-exposed and pair-fed offspring to ethanol were significantly lower than responses of normal pups. Additionally, on day 7, ethanol-exposed offspring had significantly lower responses to ethanol than pair-fed offspring and significantly lower responses to morphine than normal pups. Thus, both the prenatal ethanol and pair-feeding treatments suppressed pituitary-adrenal responsiveness of 5 and 7 day-old neonates to the drug challenges. This is in marked contrast to our previous findings for adult prenatally ethanol-exposed offspring whose pituitary-adrenal responses to the same drugs, as well as to other stressors, are consistently enhanced in comparison to pair-fed derived rats, whose responses in adulthood no longer differ from normals.
D000818:Animals; D000831:Animals, Newborn; D003345:Corticosterone / Q000097:blood; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D009020:Morphine / Q000494:pharmacology*; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D011919:Rats, Inbred Strains
D000431:Ethanol; D009020:Morphine; D003345:Corticosterone