[Human catabolism of medium and long chain triglycerides after intravenous infusion]

The metabolic rate of intravenously administered middle-chain and long-chain triglycerides has been tested in metabolically healthy adult subjects. After an infusion period of three hours (infusion rate 0.22 g triglyceride/kg body-weight and hour) the metabolic rate of long-chain triglycerides was 16.4 mg/kg body-weight and hour. The metabolic rate of the middle-chain triglycerides (infusion rate 0.056 g/kg body-weight and hour) administered in a mixture with long-chain triglycerides was slower: 4.8 mg/kg body-weight and hour. Even under these conditions, middle-chain triglycerides increased ketonemia and ketonuria. Furthermore, the acetate level in blood increased significantly. Infusion of lipids have a strong effect on amino-acid levels in blood. The concentration of alanine, leucine, isoleucine are decreased, whereas the concentration of glutamate increases at the same time. Under clinical parameters only a mild leucocytosis has been found. Our data suggest that the metabolic rate of middle-chain triglycerides is according to their low plasma concentration slow, nevertheless, the ketogenesis is significantly higher if middle-chain triglycerides are infused in a mixture with long-chain triglycerides.