BRANCHED-CHAIN ALPHA-KETO ACID DEHYDROGENASE KINASE CONTENT IN RAT SKELETAL-MUSCLE IS DECREASED BY ENDURANCE TRAINING

The activity state of branched-chain alpha-keto acid dehydrogenase com plex in skeletal muscle was elevated by running exercise in trained an d untrained rats, but level of this elevation was significantly greate r in the former than in the latter. To elucidate the mechanism of the training effect on the exercise-induced activation of the complex, a p rotein amount of branched-chain alpha-keto acid dehydrogenase kinase, which is responsible for inactivation of the complex by phosphorylatio n, in the muscle was measured by the Western blot analysis. Endurance training decreased the content of the kinase protein in the muscle by similar to 30%, suggesting that this decrease is involved in the mecha nisms for greater activation of the complex by exercise in trained rat s.