ETHANOL-INDUCED ALTERATIONS IN ERYTHROCYTE-MEMBRANE PHOSPHOLIPID-COMPOSITION

Ethanol's effects on erythrocyte membrane lipid composition were examined in male squirrel monkeys divided into three groups receiving three different regimens: Controls were fed a chemically defined liquid diet, and low and high ethanol primates were given diets with vodka substituted isocalorically for 12% and 24% of calories, respectively. After membrane lipid extraction, phospholipid mass, class composition, and fatty acid profiles were measured in each group. Although there were no differences in the total phospholipid mass, the low ethanol primates had significantly elevated phosphatidylethanolamine in their membranes as compared with the other monkeys. Membrane phospholipid fatty acid profiles showed no differences among the three groups. There were also no differences in the animals' plasma liver enzymes. Results of this investigation suggest that, despite the absence of nutritional deficiencies and liver malfunction, low amounts (12%) of dietary ethanol cause elevations in phosphatidylethanolamine that may represent a specific change in the membrane's inner leaflet where this phospholipid is located. These results may have clinical significance because ethanol-induced modifications in membrane lipids may contribute to alterations in fluidity and lead to pathologic changes in function.