Action of Insulin on Release of Fatty Acids From Tissue Stores

Abstract

The mechanism by which carbohydrate utilization reduces the concentration of nonesterified fatty acids (NEFA) in plasma was studied by comparing the clearance of C¹⁴-labeled palmitic acid before and after the administration of insulin. The rate of disappearance from blood of a single injection of C¹⁴-labeled palmitic acid was identical before and after an intravenous injection of insulin (0.1 µ/kg) although the expected significant fall in total NEFA concentration occurred. When steady concentration of labeled NEFA was maintained by a constant infusion, the administration of insulin produced a significant increase in specific activity. It is, therefore, concluded that insulin decreases the release of fatty acids from tissue stores but does not accelerated their removal from blood.