The effects of palmitylcarnitine on hepatic fatty acid synthesis and on acetyl CoA carboxylase activity

Abstract

Depressed rates of fatty acid synthesis from acetate-1-C 14 by liver preparations from starved rats were increased approximately 13-fold by addition of (+)-palmitylcarnitine but not by (−)-palmitylcarnitine. In contrast, malonyl-2-C 14 CoA incorporation into fatty acids was not decreased by starvation, and it was increased only 30% by (+)-palmitylcarnitine. Partially purified acetyl CoA carboxylase activity was enhanced by either (+)- or (−)-palmitylcarnitine in both the presence and absence of citrate or malonate. Palmityl CoA inhibition could be partially overcome by (+)- or (−)-palmitylcarnitine addition to the isolated enzyme system. A possible role of palmitylcarnitine in the regulation of fatty acid synthesis was discussed.