Abstract
This study was conducted to investigate the long-term effect of dietary medium-chain triglyceride (MCT) as compared with that of corn oil feeding on lipid metabolism in rats. Both serum choles-terol and triglyceride levels in MCT-fed rats showed significant decrease during the experimental period of eight weeks, although liver cholesterol and triglyceride contents were not distinguishable between the two groups. Significant elevation of the activity of lipogenic enzymes, such as fatty acid synthetase (FAS) and malic enzyme (ME) of the liver, was ob-served in MCT-fed rats without any fat accumulation of the liver (fatty liver). The increase of lipogenic enzyme activity was accompanied by a significant reduction of essential fatty acids (EFA) such as 18:2 (ω6) and 20:4 (ω6) in total liver lipid. In contrast, hepatic β-hydroxy-β-methylglutaryl CoA (HMG-CoA) reductase activity was significantly de-creased in MCT-fed rats, that would play an important role in achieving hypocholesterolemia. From these results obtained in a long-term ex-periment, it is concluded that exogenous MCT depresses the key en-zyme catalyzing cholesterol synthesis with a concomitant elevation of lipogenic enzyme activity in the rat liver.
