PYRUVATE-DEHYDROGENASE ACTIVATION IN ADIPOCYTE MITOCHONDRIA BY AN INSULIN-GENERATED MEDIATOR FROM MUSCLE

Material in a Chromatographic fraction from an extract of insulintreated muscle stimulated pyruvate dehydrogenase activity in adipocyte mitochondria. This action was similar to insulin's activation of the enzyme in a plasma membrane-mitochondria mixture. Neither the Chromatographic fraction nor insulin required adenosine triphosphate or magnesium ion (Mg2+), suggesting that both agents acted through a calcium-sensitive phosphatase. This fraction may contain a chemical mediator of insulin action.