Effects of High-Fat Diets Containing Different Fats on Cholesterol Metabolism in Starvation-Refeeding Rats

The present study was performed to investegate the effects of high-fat diets containing different fats on cholesterol metabolism in starvation-refeeding rats. Forty female Donryu rats were divided into two groups and then fed high-fat diets containing beef tallow or corn oil without cholesterol for 14 days. Then, 10 rats from each group were divided into high-cholesterol and cholesterol-free groups (Experiment 1). Another 10 rats from beef tallow and corn oil groups were divided into high-cholesterol and high-cholesterol-cholestyramine groups (Experiment 2). All rats were fasted for 2 days followed by 3 days of feeding. In Experiment 1, the high-cholesterol diet caused significant increases in plasma total cholesterol and cholesteryl ester concentrations in the beef tallow diet group. In Experiment 2, dietary cholestyramine markedly decreased plasma and liver cholesterol levels; however, these cholesterol levels were higher in the beef tallow diet group even if cholestyramine was added to the diet. These results suggested that the cholesterollowering effect of dietary corn oil may not be due solely to reabsorption of bile acids. This study suggested that high-fat diets containing different fats affected cholesterol metabolism under conditions of starvation-refeeding.