Utilization of Glucose,Octanoate and Palmitate by Normal Rat Aorta,and the Effect of these Acids and of Albumin on Glucose Metabolism

Abstract

Summary

Influence of octanoate and palmitate on the uilization of glucose by rat aortic tissue was examined. Octanoate but not palmitate depressed the oxidation of glucose-U-¹⁴C to CO_2. No effect was exerted by these fatty acids on glucose uptake, conversion of glucose to lipids, or oxygen uptake. Commercial bovine serum albumin, used as a carrier for these acids, depressed glucose uptake, increased CO₂ production from radioactive glucose, and increased oxygen uptake. These effects were abolished with purification of albumin by dialysis and charcoal treatment. The purified albumin did, however, decrease incorporation of glucose radioactivity into tissue lipid. In a short-term experiment (18-min incubation) octanoate was oxidized to water-soluble products and CO₂ much more rapidly than was palmitate. These results suggest that oxidation of free fatty acid, at the more rapid rate observed with octanoate, has a sparing effect on the oxidation of glucose to CO₂ in aortic tissue.