THE EFFECT OF INSULIN ON NONESTERIFIED FATTY ACID RELEASE FROM THE HUMAN LEG*

Abstract

The effect of small (0.5 to 1 unit) femoral arterial injections of insulin on arteriovenous (A-V) difference for nonesterified fatty acids (NEFA) in this extremity has been studied in 6 human subjects, using the opposite, uninjected limb for comparison. Arterial NEFA level dropped significantly within 20 minutes after injection. The A-V difference in the injected limb changed from a negative value to a frequently positive value, whereas the A-V difference in the control limb did not change. This difference between the injected and noninjected limbs reached a level of significance at 20 minutes after injection, thus demonstrating a distinct insulin action in the injected limb apart from the rest of the body. The observed changes are felt to reflect local suppression by insulin of NEFA release. This effect is accompanied by a local increase in glucose uptake.