Stress during pregnancy alters the offspring hypothalamic, pituitary, adrenal, and testicular response to isolation on the day of weaning

Subjecting pregnant female rats to situations that activate the hypothalami c-pituitary-adrenal (HPA) axis can have long-term effects on the developmen t of the offspring. Restraint under bright lights is a common method of str essing pregnant females that results in consistent behavioral changes in th e offspring. We investigated the effects of gestationally administered rest raint, bright lights, and heat on the HPA axis response of 21-day-old offsp ring following exposure to isolation in a novel environment or under restin g conditions. Corticotropin-releasing factor titers in the hypothalamus wer e unaffected following isolation. Nonetheless, adrenocorticotropin hormone (ACTH) was found to be lower in the gestationally stressed offspring prior to or following the isolation period. Corticosterone was attenuated in gest ationally stressed offspring following the postnatal stressor and there was also a tendency for the gestationally stressed females to have lower conce ntrations of aldosterone. Plasmatic testosterone levels were higher in the gestationally stressed males following the period of isolation. The present data suggest that the HPA axis of the offspring is differentially affected by the gestational stress procedure, that is, it is attenuated at the leve l of the pituitary and adrenal, but not at the level of the hypothalamus. T hese data have implications for behavioral differences observed in gestatio nally stressed animals. (C) 1999 Elsevier Science Inc. All rights reserved.