Bile acids. XXXVII. Identification of the 3β isomers of allocholic and allochenodeoxycholic acids as metabolites of 5α-cholestanol in the rat

Abstract

Bile was collected for 18–24 days from adult male rats with cannulated bile ducts that had received intraperitoneally 0.8 mg of 5α-[4-14C, 3α-3H]cholestan-3β-ol. Bile from the first 2 days containing 14.2% of the administered 14C and 3.3% of the 3H was hydrolyzed, and the bile acids were separated by acetic acid partition chromatography. The previously unidentified metabolite more polar than cholic and allocholic acids was identified by isotopic dilution as 3β,7α,l2α-trihydroxy-5a-cholanic acid and represented 3% of the biliary 14C and 15% of the 3H. Similarly, 3β,7α-dihydroxy-5α-cholanic acid was identified in fractions more polar than allochenodeoxycholic acid and represented 0.6% of the biliary 14C and 8% of the 3H. More polar fractions contained 4% of the 14C and 31% of the 3H in unidentified metabolites.

Keywords

• bile fistula rat
• cholestanol metabolism
• isomeric allocholanic acid
• 5α-cholanic acids
• 5α-[4-14C, 3α-3H]cholestan-3β-ol
• 3β-hydroxy allocholanic acids