Evidence that acetaldehyde irreversibly impairs glycoprotein metabolism in liver slices

When liver slices were incubated for 1 hr in a medium containing either acetaldehyde or ethanol and then switched to a fresh medium free from acetaldehyde but containing the appropriate radioactive precursors and reincubated for 3 additional hr, a decreased incorporation of both [14C]glucosamine and [14C]leucine into hepatocellular and secretory proteins was observed. Further studies were carried out comparing the inhibitory effects of ethanol and acetaldehyde on drug metabolism. Higher concentrations of ethanol were necessary to impair aniline hydroxylation when compared to its effect on glycoprotein metabolism. Acetaldehyde did not affect aniline metabolism, suggesting some specificity for its effect on intracellular metabolic functions. Our results show that the acetaldehyde-induced inhibition of glycoprotein synthesis is irreversible under these short term experimental conditions and is not dependent on the physical presence of acetaldehyde in the incubation medium.