We were interested in knowing whether long-term administration of arginine and leucine to rats with endurance exercise might increase more mitochondrial enzymes of oxidative metabolism compared to the rats with endurance exercise only (no administration). Rats were trained by treadmill for 5 weeks with (TD group) or without (T group) oral administration of a mixture of arginine, leucine and carnitine. Rats without treatments were used as a control. Various biochemical parameters were measured and compared in the mitochondria isolated from homogenates of hind muscles of the rats by differential centrifugation. Mitochondrial proteins per muscle wet weight increased significantly in T and TD group compared to C group. The activities of the marker enzymes of mitochondria including cytochrome C oxidase did not changed. The content of cytochromes of mitochondria were somewhat elevated in T and TD. The mitochondrial respiration with various oxidative substrates increased in T and TD. However, all of the measured values indicated that there were no difference between T and TD. We expect that further study using different experimental protocols or with other chemical compounds may lead to a discovery of such promotive effect on mitochondrial protein accumulation.

DESCENTE SPORTS SCIENCE Vol.9/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE