ADRENALECTOMY BUT NOT ADRENAL DEMEDULLATION DURING PREGNANCY PREVENTSTHE GROWTH-RETARDING EFFECTS OF FETAL ALCOHOL EXPOSURE

Growth retardation, both in the prenatal and the early neonatal period , is a consistent feature of fetal alcohol exposure, but the mechanism by which alcohol affects growth has not been eludicated. Because othe r stressors-such as maternal restraint and neonatal glucocorticoid tre atment-can also affect growth, we examined the effect of ethanol on pu p birthweight under two experimental conditions that altered maternal adrenal function. In the first study when dams were adrenalectomized a nd given low replacement doses of dexamethasone, the ethanol-exposed o ffspring of the adrenalectomized dams had birthweights similar to thos e of dams maintained on regular lab chow diets. In a second study, we found that maternal adrenal demedullation did not alter the reduction in birthweight produced by fetal ethanol exposure. The results suggest that the effects of ethanol on fetal growth may be mediated in part t hrough ethanol-induced changes in the function of the maternal adrenal cortex.