The Effect of Insulin on the Incorporation of D-Glucose-U-14C into the Lipids of the Rat Aorta In Vivo

Abstract

Recent studies have shown that an excessive insulin response to glucose is common in subjects with premature atherosclerosis. To test whether insulin may influence the metabolism of the arterial wall, the effect of insulin on the incorporation of radiolabeled glucose into arterial lipids in vivo was studied in rats. Intravenous injection of 10,000 µ units of insulin per 100 gram body weight resulted in increased incorporation of D-glucose-U-14C into triglyceride 60 and 90 minutes after injection, and into triglyceride and free fatty acids 180 and 360 minutes after injection. No effect on radioactive cholesterol was found. There was no correlation between serum and aortic radioactivities 90 and 360 minutes after injection, suggesting that the effect of insulin on arterial lipids did not originate from changes in serum lipids. Thus the hyperinsulinism found in human subjects with atheromatous vascular disease may have a role in the pathogenesis of atherosclerosis.