Prenatal ethanol effects: Sex differences in offspring stress responsiveness

Abstract

Previous studies have shown that offspring prenatally exposed to ethanol are hyperresponsive to stressors in adulthood, and have suggested that females are typically more affected than males. The present study was undertaken to investigate further this apparent sex difference in prenatal ethanol effects on stress responsiveness. Male and female offspring from prenatal ethanol-exposed (E), pair-fed (PF), and ad lib-fed control (C) conditions were tested in adulthood to determine adrenocortical responses to a prolonged (4-h) restraint stress. There were no significant differences in corticoid responsiveness among females from the three treatment groups. All females showed a marked increase in plasma corticosterone at 30 min, and corticoid levels remained elevated through 150-min restraint. By 180 min, all females showed a significant corticoid decrease, although corticosterone remained elevated over basal levels throughout the 240-min stress period. For males, in contrast, there were significant differences among groups. All males showed a significant corticoid increase over basal levels at 30 min, and corticoids remained significantly elevated through 90-min restraint. By 120 min, PF and C males showed a significant corticoid decrease although corticoids never returned to basal levels during the 240-min restraint period. E males, however, showed no significant decrease from peak corticosterone levels throughout the 240-min restraint stress. These data indicate that pituitary-adrenal hyperresponsiveness is not limited to fetal ethanol-exposed females, but may be demonstrated in fetal ethanol-exposed males under appropriate conditions. The parameters of the test situation, including the nature and intensity of the stressor and the time course of the response during stress or recovery from stress that is measured, appear to be critical in revealing differential effects of prenatal ethanol exposure on males and females.