Effects of medium-chain triglycerides on gluconeogenesis and ureagenesis in weaned rats fed a high fat diet

• MCT feeding enhances gluconeogenesis via increase of glutamic alanine transaminase.
• The MCT feeding is accompanied by increased urea formation.
• Metabolic pathway of gluconeogenesis by MCT is different from that of corn oil.

We explored the effects of Medium-chain triglycerides (MCT) on gluconeogenesis and ureagenesis in the liver of weaned male rats fed high fat, carbohydrate-free diets. The rats of three experimental groups and control were fed for 10 days. The diets were high fat, carbohydrate-free diets consisting either of a corn oil or MCT, and high protein carbohydrate-free diet and a control (high carbohydrate) diet. The hepatic glucose-6-phosphatase (G6Pase) activity increased in the experimental groups. Despite the elevated G6Pase activity in these groups, hepatic activities of glutamic alanine transaminase (GAT), pyruvate carboxylase (PC) and arginase differed among the experimental groups. The HF-corn oil rats showed elevation of PC activity, but no elevation of GAT activity, and the lowest arginase activity among the three groups. The HF-MCT diet-fed rats showed higher GAT and arginase activities than the HF-corn oil group. In the HP diet-fed rats, GAT and arginase activities enhanced, PC did not.