Effect of chronic ethanol abuse on the physico-chemical properties of erythrocyte membranes in man.

Chronic alcoholics (greater than 150 g/day) showing minor serum and histological changes have been studied, compared to healthy non alcoholic subjects, and the following parameters have been considered: S. (Serum)cholesterol (CH), S.phospholipids (PH), S.folate level, and mean corpuscular volume (MCV). Erythrocyte ghosts have been studied for CH and PH content and membrane fluidity using diphenylhexatriene as a probe. All alcoholics showed decreased fluidity of red cell membrane with increased CH/PH ratio, even in patients showing normal MCV or minimal alterations of functional tests, suggesting that changes in red cell membrane fluidity represent an early sign of ethanol abuse. These likely reflect the diffuse interaction of ethanol with biological membranes. The administration of N5-Methyltetrahydrofolate produced an increase of membrane fluidity over the 3 weeks considered, associated with modest changes of MCV. The latter were delayed with respect to changes in fluidity. If changes of red cell membrane fluidity are a sensitive index of alcohol abuse, they could be a useful marker for detection and follow-up of chronic alcoholism.