The formation of lithocholic acid, chenodeoxycholic acid and α- and β-muricholic acids from cholesterol incubated with rat-liver mitochondria

Abstract

When rat-liver mitochondria were incubated with [4-C14]cholesterol in the presence of a soluble supernatant fraction, various steroids more polar than cholesterol were formed. These included 3[beta]-hydroxycholest-5-en-26-oic acid, 3[beta]-hydroxychol-5-enoic acid, lithocholic acid, chenodeoxycholic acid and [alpha]- and [beta]-muricholic acids. All the radioactive C24 bile acids recovered were in conjugated form, probably as taurine conjugates. The formation of 3[beta]-hydroxy-chol-5-enoic acid from cholesterol shows that liver mitochondria are capable of carrying out the oxidative removal of the isopropyl unit of the side chain before any modification has occurred in the ring system.