Build-Up and Regression of Inhibitory Effects of Cholic Acid on in vivo Liver Cholesterol Synthesis.

Abstract

A study of sequence of events during initiation and regression of inhibition of cholesterol synthesis by dietary cholic acid was made in rats. In the initiation study, increases of liver cholesterol and serum bile acid levels paralleled decreases of liver cholesterol-x-C¹⁴ activity. There was a decrease in liver phospholipid during the same time interval. In the regression study, serum bile acid and liver cholesterol returned to control levels more rapidly than the rate of liver cholesterol synthesis. The results suggest that dietary cholic acid initially elevates liver cholesterol, which in turn leads to the inhibition of acetate-1-C¹⁴ incorporation into liver cholesterol.