Hyperresponsiveness to stress: differential effects of prenatal ethanol on males and females.

In this study we investigated the hypothesis that pituitary-adrenal response inhibition is compromised in animals prenatally exposed to ethanol. In the first experiment, we examined whether opportunity to perform a consummatory response reduces the adrenocortical response to a novel test cage. Animals were water deprived for 24 hr and tested in one of three conditions: (a) removed from home cage, blood sample obtained immediately; (b) placed into empty novel cage, blood sample obtained 30 min later; (c) placed into novel cage with water available, blood sample obtained 30 min later. All animals showed an increase in corticoids over basal levels following 24-hr water deprivation, and placement into a novel cage produced a further significant increase in corticosterone. Opportunity to drink reduced the corticosterone response to novelty for all males. However, fetal ethanol-exposed females showed significantly less attenuation of their corticosterone response to novelty than both pair-fed and control females. In the second experiment, we examined adrenocortical habituation to a stressful stimulus. Animals were restrained in plastic tubes which restricted movement, and blood samples were obtained following 30 or 60 min of restraint. All animals showed significant corticoid elevations at 30 min. Males showed no change in corticoids from 30 to 60 min while both pair-fed and control females showed a corticoid decrease at 60 min. Fetal ethanol-exposed females, however, showed no significant corticoid decrease at 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)