On the Oxidation of Cholesterol in Liver Mitochondrial Preparations. Bile Acids and Steroids 99.

Abstract

The oxidation of 4-C14- and 26-C14-cholesterol has been studied in mitochondrial preparations of mouse and rat liver. The simultaneous occurrence of autoxidation and enzymatic oxidation of the added labeled cholesterol, indicated by experiments on the metabolism of cholesterol in different cellfractions of liver and in mitochondria of heart and kidney, has been ascertained by analyses of the labeled products formed under non-enzymatic and "enzymatic" conditions. Among autoxidatively formed products 3/3, 5a, 6B-trihydroxycholestane, 7a-hydroxycholesterol, 7B-hydroxycholesterol and 7-ketocholesterol have been identified. Two major enzymically formed compounds both retaining the C37-side-chain, have been isolated. One is less polar than 7a-hydroxycholesterol but more polar than 7-ketocholesterol, while the other shows chromatographic properties similar to a neutral trihydroxy-C3Y-sterol. This latter compound is metabolized to chenodeoxycholic but not cholic acid in the bile-fistula rat.