Effect of ethanol administration on fatty acid desaturation.

The effect of ethanol on the fatty acid desaturation by rat liver has been studied using liquid diets of different composition. Acute ethanol administration increased triacylglycerols of total liver lipids, but did not modify significantly the lipidic composition of microsomes. The delta 6 and delta 5 desaturases were inhibited by ethanol whereas the delta 9 desaturase and fatty acid synthetase were apparently modified only by diet composition. NADH-cytochrome (cyt.) c reductase was partially inhibited, whereas NADH-cyt. b5 reductase remained practically unaltered and NADPH-cyt. c reductase activity was enhanced. Decreased electrons supplied by the microsomal cyt. b5 electron transport chain would not be the reason for the inhibition of delta 6 and delta 5 desaturases by ethanol.