The effect of insulin on the incorporation of sodium (1-14C)-acetate into the lipids of the rat aorta

Summary Experiments were performed to test the hypothesis that insulin has a role in the pathogenesis of atherosclerosis. Rats were injected intravenously with sodium (1-¹⁴C)-acetate (10 Ci per 100 g weight) with and without insulin (100000 units per 100 g weight). After one hour, they were killed, and the lipids extracted from the cleaned aortas. The lipids were separated by thin layer chromatography, and the radioactivity in the total lipids and the lipid fractions was measured. The results showed that insulin stimulated the incorporation of sodium (1-¹⁴C)-acetate into total lipids, cholesterol and phospholipids to a significant extent. Incorporation into triglyceride just failed to reach statistical significance. These results are compatible with some of the features of human atherosclerosis, and support the hypothesis that insulin and atheroma are causally linked. The finding that insulin had an effect on cholesterol metabolism was unexpected and warrants further investigation.This work formed part of a thesis accepted for the degree of MD (Belfast) 1970.