Effect of Estradiol and Testosterone on the Metabolism of Linoleic Acid in Essential Fatty Acid-deficient Rats

Publisher Website
Google Scholar
Abstract
The distribution of activity in carcass, liver and plasma from 14C-labeled linoleic acid given orally to 3 groups of essential fatty acid-deficient rats (male castrates (O group), castrates treated with estradiol (E), and castrates treated with testosterone (T)) was measured 6 hours after administration. More than 50% of the total incorporated radioactivity was observed in liver triglycerides and phospholipid. The specific activities of both cholesteryl ester and phospholipid were higher in plasma than in liver, but the triglycerides of liver had a much higher specific activity than the triglycerides of plasma. The cholesteryl ester in plasma and the phospholipid of liver had acquired the greatest proportion of 14C-arachidonic acid. The E group incorporated a higher proportion of radioactivity into the arachidonic acid of the liver phospholipid than the T group. Ratio of specific activity of linoleic to arachidonic was significantly lower in one of 2 liver lecithin fractions in the E group than in the T group. This fraction was richer in stearic and arachidonic acids in contrast with a less polar fraction rich in palmitic and linoleic acids. Possible implications with respect to the effects of the gonadal hormones on the conversion of linoleic to arachidonic acid are discussed.