Insulin and lipogenesis in rat adipocytes. I. Effect of insulin incubation on lipid synthesis by isolated rat adipocytes.

To assess the effect of insulin on lipid synthesis in isolated rat adipocytes, cells were preincubated for 3 h with high concentrations (16.6 nM) of the hormone and lipogenesis measured through 14C-acetate incorporation into lipids, analyzing at the same time the activity of some lipogenic enzymes. It was found that insulin induced not only a decrease in the number of insulin receptors but a 30% loss in basal and insulin-stimulated acetate incorporation into total lipids as well as a decrease in the activities of enzymes related to the novo fatty acid synthesis pathway as malic enzyme and glucose-6-phosphate dehydrogenase.