The purpose of the study was to find an effect of Medium Chain Triglycerids (MCT) diet on cholesterol metabolism in rat. Sprague-Dawley rats were fed two different diets containing MCT(trioctanoate) and corn oil respectively. After feeding to each group for four weeks, the levels of serum and liver cholesterol, the excretion rates of fecal and biliary steroids, and also bile acid composition were investigated. The results obtained from the study are as follows : (1) The average body weight gain in MCT group was almost same as that in the corn oil group. (2) The concentration of serum cholesterol in MCT group was lower than that in the corn oil group. Therefore it is confirmed that the cholesterol lowing action of MCT diet was practically high. (3) The concentrations of liver cholesterol and Triglyceride in MCT group were almost same as that in the corn oil group. Therefore it is thought that the level of liver lipids was not influenced by the difference of diet in this study. (4) The excretion rate of fecal neutral steroid in MCT group was significantly lower than that in the corn oil group, while the rate of fecal bile acid excretion was about same in both MCT and corn oil group. (5) The composition rates of fecal bile acid such as cholic acid, chenodeoxycholic acid and deoxycholic acid, a secondary acid of cholic acid, in MCT group were significantly lower than that in the corn oil group. (6) The excretion rates of biliary cholesterol and bile acid in MCT group were significantly higher than that in the corn oil group, while the composition rates of biliary bile acid such as chenoddeoxycholic acid and deoxycholic acid in MCT group were significantly higher than that in the corn oil group.

The purpose of the study was to find an effect of medium chain triglyceride (MCT)diet on the serum lipids and lipoprotein of Sprague-Dawley rats when the were fed with cholesterol. All experiment-groups were fed with different diet such as soybean oil, shortening,MCT and MCT mixed with oil respectively. After fed to each group, the levels of serum lipids and lipoprotein among fed rats were examined and the data from the experiment were compared with a control group. The results obtained from the study are as follows : (1) The average boby weight gain in MCT diet and soybean oil diet groups were lighter than that of the control group, while the food efficiency ratio in each experimental diet group was almost same as than in the control group. (2) Total cholesterol levels in serum of all experimental diet groups were lower than that of the control group except the level in shortening diet group. Especially, the levels of total cholesterol in MCT diet and soybean oil diet groups were significantly lower than that of the control group. (3) VLDL, LDL-cholesterol levels of all experimental groups were almost same except the case of the MCT diet and soybean oil diet group which was significantly low. (4) The ratio of VLDL, LDL-cholesterol to HDL-cholesterol, so called, atherogenic index in serum of MCT and soybean oil diet groups were significantly lower than that of the control group. (5) The ratio of total cholesterol to phospholipids in serum of MCT diet group was decreased, because total cholesterol levels were decreased more than phospolipid levels. (6) The ratio of the serum VLDL, LDL to HDL in MCT diet group. in MCT and soybean oil mixed diet group, and in soybean diet group was decreased. In other wards, it means that the decrease of the serum VLDL, LDL in each group and the increase of the serum HDL.