GEMFIBROZIL MODIFIES ACYL COMPOSITION OF LIVER MICROSOMAL PHOSPHOLIPIDS FROM GUINEA-PIGS WITHOUT PROMOTING PEROXISOMAL PROLIFERATION

Treatment with gemfibrozil modifies acyl composition of hepatic micros omal phosphatidylcholine and phosphatidylethanolamine in guinea-pigs. Palmitic (16:0) and palmitoleic (16:1) fatty acids are increased, and stearic (18:0) and oleic (18:1) are decreased; further, while linoleic acid [18:2 (n-6)] is increased by gemfibrozil treatment, the other co nstituents of the n-6 fatty acids family, including arachidonic acid [ 20:4 (n-6)], are decreased. As gemfibrozil is a potent inhibitor of fa tty acid elongation in vitro (Sanchez et al., FEBS Lett 300: 89-92, 19 92), the inhibition of this enzyme system by gemfibrozil treatment cou ld be responsible for the observed results in vivo. These changes in f atty acid composition are accompanied by a decrease in serum lipids an d, more important, are independent of peroxisomal proliferation.