Effects of Glucose, Medium-Chain Triglycerides and Long-Chain Triglycerides on Branched-Chain Amino and Keto Acid Metabolism in Septic Rats

Abstract

The effects of administering medium-chain fatty acids (MCT), long-chain fatty acids (LCT), and glucose on plasma and skeletal muscle branched-chain amino acid (BCAA) and branchedchain alpha-keto acid (BCKA) metabolism were studied in septic rats and sham-operated controls. The plasma BCAA level decreased in the septic rats as compared with the controls, and the decrease was significant in MCTand LCT-treated animals. In contrast, the skeletal muscle BCAA concentration increased significantly in all septic rats, especially in those treated with LCT. The plasma and skeletal muscle BCKA concentrations increased in all groups, with the increases in the muscle being significant. In the septic animals, the plasma BCAA concentration was markedly reduced, but the skeletal muscle BCAA concentration increased significantly in MCTand LCT-treated groups in comparison with the glucose-treated group. There were no significant differences in the plasma BCKA concentration among the various treatments, but the muscle BCKA concentration was significantly higher in the LCT-treated than in the glucose-treated group. The ratios of the blood versus tissue concentrations of BCAA and BCKA suggested that they were released in large amounts from the tissues into the blood in septic animals, and this tendency was more notable with BCKA. However, these changes in the plasma and skeletal muscle BCAA and BCKA metabolism were the smallest in the glucose-treated animals, suggesting that glucose is more beneficial than LCT or MCT for BCAA and BCKA metabolism and for the prevention of protein breakdown in sepsis.