Evidence for a Common Hepatic Cholesterol Precursor Site for Cholic and Chenodeoxycholic Acid Synthesis in Man 1

Summary

Bile fistula patients were administered [¹⁴C]cholesterol and labeled mevalonic acid by constant infusion (for 5 hr) or by intravenous pulse. Bile was collected at frequent time intervals. The specific activities of newly synthesized cholic and chenodeoxycholic acids were virtually identical at all time periods (up to 24 hr). These observations provide evidence for the presence of a common cholesterol substrate pool for primary bile acid synthesis in man. Both cholic and chenodeoxycholic acids appear to be synthesized via the 7α-hydroxy-cholesterol pathway.