Effect of dietary saturated fatty acids on intracellular free fatty acids and kinetic properties of hormone-sensitive lipase of rat adipocytes

Abstract

Experiments were conducted to examine the effects of dietary saturated fatty acids on the intracellular free fatty acid concentration and composition and on the kinetic parameters of hormone-sensitive lipase of rat adipocytes. Animals were fed for 4 wk 14% coconut oil, beef fat or safflower oil and 2% corn oil in a purified diet. Adipocytes of animals fed the coconut oil diet contained higher basal level of intracellular free fatty acids than those of animals fed other beef fat or safflower oil diets. Norepinephrine (10(-5) M) stimulated the basal intracellular free fatty acid concentration by 2.3-3.4-fold in adipocytes from animals fed saturated fatty acids, compared with 6.4-fold in those of animals fed the safflower oil diet. The concentrations of intracellular free fatty acids in adipocytes of experimental animals after stimulation with 10(-5) M norepinephrine, however, were not significantly different. The intracellular free fatty acid pool of adipocytes of animals fed the saturated fatty acids had more palmitic acid and less linoleic acid than those of safflower oil-fed animals. The results indicate that type of dietary fat had no effect on kinetic properties of hormone-sensitive lipase.