Effect of ethanol intake on the incorporation of labelled amino acids into liver protein

Abstract

Male Wistar rats were given ethanol to provide approximately 30 per cent of the total calories consumed. Sucrose or lipids replaced ethanol isocalorically in controls. Ten per cent of the calories were usually provided by protein, except for in one experiment where both treated and control animals received 25 per cent of their calories from protein. The diets were given for periods up to 35 days. When ethanol replaced sucrose isocalorically, incorporation of labelled amino acids into liver cell protein was reduced after treatment for 30 days, but not after treatment for 1 or 3 days. The reduced incorporation was present both in the presence of ethanol and 24 hr after the last intake of alcohol. When ethanol replaced lipids isocalorically, the same reduction of protein labelling was found as when sucrose was replaced, after treatment for 35 days. When both ethanol-treated and controls were given a protein-rich diet for 35 days, ethanol treatment caused the same reduction of amino acid incorporation into protein, as when both groups were fed a low-protein diet. It is concluded that long-term ethanol treatment mediates a reduction of protein synthesis in the liver. This reduction requires some time to develop, is due to the inclusion of ethanol in the diet and is not counteracted by a high-protein diet.