DIRECT EVIDENCE FOR THE OXIDATION OF FREE FATTY ACIDS BY PERIPHERAL TISSUES*

Abstract

Palmitic acid-1-C14 was injected into the brachial artery of normal fasting subjects. Radiopalmitate and C14O2 activity was measured in arterial blood and in venous blood of experimental and control forearm. After discontinuance of radiopalmitate infusion, a large negative C14 O2 difference was observed in the experimental (but not in the control) forearm. Simultaneously, a much smaller but still negative arteriovenous difference of radiopalmitate was observed. Exercise of the forearm increased the arteriovenous difference. The data provide direct evidence for the oxidation of fatty acids by peripheral tissues in man.