The formation of cholest-5-ene-3 ,26-diol as an intermediate in the conversion of cholesterol into bile acids by liver mitochondria.
1. When [(14)C]cholesterol was incubated with rat liver mitochondria, radioactive 26-hydroxycholesterol, 3beta-hydroxychol-5-enoic acid and other bile acids were isolated from the incubation mixture. 2. In the absence of added 26-hydroxycholesterol, the specific radioactivity of the 26-hydroxycholesterol formed from [(14)C]cholesterol during the incubation was higher than that of the 3beta-hydroxychol-5-enoic acid. Addition of increasing amounts of 26-hydroxycholesterol led to a progressive fall in the specific radioactivity, and to a progressive increase in the mass, of the 3beta-hydroxychol-5-enoic acid recovered at the end of the incubation. 3. It is concluded that 26-hydroxycholesterol is an intermediate in the formation of 3beta-hydroxychol-5-enoic acid from cholesterol. 4. Comparison of the specific radioactivity of the 26-hydroxycholesterol formed in the incubation mixture with that of the added [(14)C]cholesterol indicates that endogenous cholesterol in mitochondria is accessible to cholesterol 26-hydroxylase.
D000107:Acetylation; D000818:Animals; D001647:Bile Acids and Salts / Q000096:biosynthesis*; D002247:Carbon Isotopes; D002458:Cell Fractionation; D002498:Centrifugation; D002776:Cholestanes / Q000096:biosynthesis*; D002784:Cholesterol / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D051381:Rats; D013261:Sterols / Q000096:biosynthesis*; D014316:Tritium
D001647:Bile Acids and Salts; D002247:Carbon Isotopes; D002776:Cholestanes; D013261:Sterols; D014316:Tritium; D002784:Cholesterol