The Effects of‘ Muscle ExtractrJ on the Oxidation of Pnlmitic Acid by Liver Slices and Homogenates¹

Abstract

Summary and Conclnsions. A partially purified, protein‐free rat muscle extract both raised the oxygen consumption and increased the conversion rate of C 14 ‐carboxyl‐labeled palmitic acid by liver slices and homogenates. It was shown that the active factor(s) induced a relatively higher total activity in ketones than in CO 2 when the C 14 ‐labeled substrates were glucose, acetate, or palmitate. The presence of the factor(s) in cat plasma were demonstrated under certain conditions, and it was shown that carnitine addition to the incubation media duplicated part, but not all, of the actions of muscle extract. Various probable constituents of muscle extracts were eliminated as possible contributing factors in the effects elicited by addition of muscle extracts. The significance of the findings was discussed.