Effect of exogenous polyunsaturated fatty acids on lipogenic enzyme activity in rat liver under fixed carbohydrate consumption.

Studies were conducted to evaluate specific dampening of hyperlipogenesis (i.e. enhanced lipogenic enzyme activity of the liver in rats refed a high carbohydrate, fat-free diet: F-diet) by exogenous polyunsaturated fatty acids under fixed carbohydrate consumption. In force-feeding of rats with a linoleate-rich diet (F-diet containing 4.5% safflower oil), the lipogenic enzyme activities; fatty acid synthetase (FAS) and malic enzyme (ME) in the liver supernatant were found to be significantly lower than those in rats force-fed only an F-diet (p is less than 0.02), under conditions of identical consumption of carbohydrate. Among the various methylestery of unsaturated fatty acids administered by gastric intubation at a dose of 0.3 g per 100 g body weight, arachidonate was most potent in bringing about a significant reduction of hyperlipogenesis without seriously affecting food intakes. During the same three-day experimental period, fatty acid GLC spectra in both the liver and plasma lipids reflected the exogenous input of PUFA. Plasma total fatty acid concentration (mainly triglyceride) signigicantly decreased in the arachidonate group (p less than 0.01).