Increased activity of the hypothalamic-pituitary-adrenal axis of rats exposed to alcohol in utero: Role of altered pituitary and hypothalamic function

Prenatal exposure to ethanol (E) enhances the offspring's ACTH and corticos terone responses to stressors. Here, we determined the role of increased pi tuitary responsiveness and/or PVN neuronal activity in this phenomenon. Pre gnant rats were exposed to E vapors during days 7-18 of gestation, and we c ompared the responses of their 55-to 60-day-old offspring (E rats) to those of control (C) dams. PVN mRNA levels of the immediate early genes (IEGs) c -fos and NGFI-B, which were low under basal conditions in all groups, showe d a peak response 15 min after shocks and 45 min after LPS treatment. These responses were significantly enhanced in E, compared to C offspring of bot h genders. CRF, but not VP hnRNA Levels were also significantly higher in t he PVN of shocked E offspring. Resting median eminence content of CRF and V P, and pituitary responsiveness to CRF, were unchanged, while responsivenes s to VP was marginally increased in females. These results indicate that pr enatal alcohol selectively augments the neuronal activity of hypothalamic C RF perikarya.