SummaryThree groups of male rats were maintained on diets con taining different amounts of fat. After one week on such regimens, they were injected intraperitoneally with cholesterol-3H. During the following 28 days, the radioactivity and quantity of fecal cholesterol and its metabolites were determined. The coprostanol excretion was the about same in all groups and the bile acids excretion increased with increasing fat intake; however, compared to the fat-free group, the excretion of the injected cholesterol-3H was greater in the 3% fat group and less in the 10% fat group. Consequently, the specific radioactivity of bile acids was lower in the 10% group than in the others. The half life of labelled cholesterol was 12.6, 16.0 and 22.2 days for the 3%,10% fat and fat-free groups, respectively. Rather than a fat-free diet, a low fat diet of 3% or so, would be of more advantage in eliminating choleste rol by increasing the formation of bile acids to emulsify the fat. In the 10% fat group, however, the enlarged pool size of bile acid probably delayed cholesterol metabolism to bile acids.The influence of fat feeding on cholesterol metabolism has been reported by many investigators. The absorption of cholesterol increases with the amount of fat intake with an upper limit (1), although the fatty acid composition of the carrier fat affects the extent of sterol absorption (2). Several workers have re ported that fat influenced the biosynthesis and excretion of cholesterol, but with conflicting results. In the experiments of SABINE et al. (3) and JANSEN et al. (4) with mice, the high-fat diet suppressed cholesterol synthesis; whereas with rats, HILL et al. (5,6), using similar diets, found an increase in hepatic synthesis of cholesterol from acetate after feeding fat. BORTZ (7) also observed that fat feed ing to rats maintained on a fat-free diet brought about a decrease in fatty acid synthesis and an increase in cholesterol synthesis. Further, the composition of fatty acids such as linoleate, may influence cholesterol metabolism. (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). We found that linoleate had no effect on the half-life of cholesterol, though it lowered plasma cholesterol (20).On the other hand, the relation between the amount of fat intake and chole sterol metabolism is not so clear. Bile acids, the metabolites of cholesterol, are necessary for the digestion and absorption of fat, so fat intake may accelerate the metabolism of cholesterol. The present experiments were therefore designed to examine the effects of varied amounts of dietary fat on overall cholesterol metabolism, using fat with a balanced composition of fatty acids.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.