Effect of maternal ethanol ingestion during pregnancy and lactation on the structure and function of the postnatal rat liver plasma membrane: Assessment with [ 3H]prazosin binding to the hepatic α1-adrenergic receptors

Abstract

A liquid low-fat nutritionally adequate Metrecal diet in which alcohol contributed 37% of the total calories was given to pregnant rats and maintained during lactation. Control rats were pairfed with an isocaloric sucrose-Metrecal diet. After birth, litters were killed at different ages (days 1–30), and the results showed that growth and survival of progeny from the alcohol-treated rats were adversely affected. Likewise, the wet weights of livers from such pups were consistently less than from the pair-fed controls. The yield of hepatic plasma membrane protein per wet liver weight was constant and independent of either age or diet. Using [ 3H]prazosin as radioligand, equilibrium binding studies were carried out to monitor changes in the structure and function of the plasma membrane in the new-born pups concomitant with the development of α 1-adrenergic receptors. Results obtained with the alcohol-fed pups showed that the binding affinity ( K D ) was not altered throughout. However, the receptor density ( B max) was decreased significantly. This decrease ranged from 60 to 70% in pups 6- to 15-days-old; 45% at 20 days; and 30% in pups at 25 and 30 days of age. These observations suggest that maternal ethanol ingestion affected the posrnatal development of rat liver plasma membranes. Furthermore, by using the hepatic α 1-adrenergic receptor as a metabolic probe, we deduce that a possible impairment exists in the capacity of the alcoholic progeny to respond to the hormonal action of epinephrine. Such a defect may contribute to impaired growth and metabolism in these young animals.