ETHANOL ENHANCES CHOLESTEROL-SYNTHESIS AND SECRETION IN HUMAN HEPATOMAL CELLS

Excessive consumption of alcohol leads to severe alterations of lipid metabolism, including hyperlipemia and hypercholesterolemia. Following these epidemiological observations, we investigated the effects of et hanol at the cellular level by employing a human hepatomal cell line ( HepG2) and by evaluating the biosyntheses of lipid classes from differ ent labeled precursors. Incubation of cells with 2% ethanol resulted i n a decreased labeling of phospholipids and in an increase in choleste rol synthesis and secretion. Triglyceride synthesis was increased by e thanol but their secretion in the medium was reduced, suggesting that these alterations may be related to their accumulation in the liver. T he alcohol-induced alterations of lipid metabolism are not due to its metabolite acetaldehyde and data suggest that alcohol enhances cholest erol synthesis by affecting the initial steps without increasing HMGCo A expression. The observed modifications of lipid metabolism in HepG2 may partially explain the enhanced incidence of cardiovascular disorde rs that has been associated with alcoholism. (C) 1998 Elsevier Science Inc.