Effects of chronic ethanol administration on the composition of membrane lipids in the mouse.

The relative proportions of the phospholipid fatty acids of erythrocyte membranes in mice were changed by chronic ethanol treatment and were not related to effects of the drug on nutrition, body temperature or experimental stress. Similar changes were observed using two different routes of ethanol administration and they did not reflect the metabolic effects of ethanol seen in the phospholipid fatty acids of whole liver. The observed increased content of saturated fatty acids and decreased content of polyunsaturated acids support the concept of adaptive changes taking place in the membrane during tolerance development to compensate for an increased membrane fluidity caused by ethanol. However, an increased content of the mono-unsaturated acid, octadecenoic (oleic), was found and there was no change in the cholesterol/phospholipid ratio. Other contrasting types of plasma membrane in mice showed different patterns of change in their phospholipid fatty acids during chronic ethanol administration. It is suggested that changes in membrane lipid composition could only partly account for an adaptation to ethanol-induced membrane disordering.