Effects of Cholesterol on Bile Acid Metabolism in the Rat 1

Abstract

Summary

The effects of cholesterol feeding and accumulated tissue cholesterol on bile acid metabolism in normal female rats were studied. Feeding diets supplemented with cholesterol and corn oil over the entire experimental period resulted in decreases in the cholic and chenodeoxycholic acid pool half-lives of 1.6 and 0.9 days, respectively. In experiments on rats with accumulated tissue cholesterol fed unsupplemented basal rations during the experimental period, the half-lives of these acids also decreased 1.6 and 0.9 days, respectively, from the values for normal control rats. In both the dietary and accumulated tissue cholesterol experiments, the total bile acid pool concentration was unchanged but there was an important decrease in cholic acid concentration accompanied by a compensating increase in chenodeoxycholic concentration. Studies in the animals with elevated tissue cholesterol showed that the effects on bile acid turnover were not due to increased levels of sterols in the gastrointestinal tract but were due per se to the increased tissue cholesterol levels. Dietary corn oil by itself had no effect on either turnover rates or pool sizes of the bile acids.