Changes in vitamin A status after acute ethanol administration in the rat

To evaluate the effect of acute ethanol administration on vitamin A and retinol-binding protein (RBP) status, male Sprague-Dawley rats weighing 120-200 g were given an acute dose of ethanol (6 g/kg body weight, orally) or saline after a 15- to 18-hour fast. Hepatic vitamin A was decreased by 13% (P less than 0.025) 24 hours after ethanol administration. Serum vitamin A was increased 6 hours after the ethanol dose (P less than 0.005) with a 10-fold increase in retinyl ester concentration, whereas serum RBP was slightly decreased. Saline controls showed no changes. The increase in serum retinyl esters 6 hours after the ethanol dose was found in the lipoprotein fraction (density less than 1.21). When lipoprotein removal from plasma was blocked by Triton WR-1339 ethanol administration further enhanced serum retinyl ester concentration. In rats previously given [14C] retinol, hepatic 14C-labeled vitamin A was decreased, whereas in the kidney and adipose tissue it was increased 24 hours after ethanol administration. Thus, an acute dose of ethanol increases serum vitamin A and decreases hepatic vitamin A, most likely because of increased release from the liver or decreased uptake by the liver of retinyl esters as part of the lipoproteins.