The effect of chronic ethanol administration on lipids and fatty acids in subcellular fractions of rat brain.

In this study we have investigated the proportion of lipids and of fatty acids in brain membranes and blood serum from rats which received ethanol over a long period. Nine Sprague-Dawley rats were given ethanol in their drinking water for five months. Nine age-matched rats given pure water served as controls. Subcellular fractions (myelin, synaptosomes and mitochondria) were prepared in a discontinuous gradient of sucrose from each of the 18 rats. Blood serum was collected at decapitation. The fractions were assayed for their concentrations of protein, cholesterol, phospholipids and for the proportions of fatty acids in individual phosphoglycerides. No significant differences in the concentration of the major lipids were obtained between the ethanol-exposed rats and the control rats. In the synaptosomal fraction from ethanol-exposed rats, the proportion of oleic acid in phosphatidylcholine was increased and that of arachidonic acid in phosphatidylethanolamine decreased. These two fatty acids were also changed in the blood serum and there was a significant correlation between the changes in the brain and blood serum. The results suggest that during ethanol exposure there is an increased disposition toward modification of synaptosomal membranes by changes in the blood plasma fatty acid pattern.