The pathways of bile acid synthesis in man were evaluated by studying the metabolism of 7α-hydroxycholesterol-4-14C and 26-hydroxycholesterol-16, 22-3H administered parenterally to individuals requiring external biliary drainage. Techniques for the identification of metabolites were thin-layer chromatography, column chromatography, gas-liquid chromatography with stream splitting, and crystallization to constant specific activity. It was found that both compounds were rapidly metabolized to bile acids and excreted in bile. Of the total radioactivity recovered in bile as bile acids, 87% of the 26-hydroxycholesterol-3H and 90% of the 7α-hydroxycholesterol-14C was found to be metabolized to both chenodeoxycholate and cholate. Compared to 7α-hydroxycholesterol, a greater proportion of 26-hydroxycholesterol was found to be metabolized to chenodeoxycholate.
Karl E. Anderson, Engeline Kok, Norman B. Javitt