Bile acids. XXXV. Metabolism of 5α-cholestan-3β-ol in the Mongolian gerbil

Bile acid profiles in bile, urine, and feces of a patient with cerebrotendinous xanthomatosis

Bile acid profiles of bile, urine, and feces obtained from a patient with cerebrotendinous xanthomatosis on the same day have been analyzed by gas-liquid chromatography-mass spectrometry after fractionation into groups by mode of conjugation by an ion-exchange chromatography. The predominant biliary bile acid was cholic acid conjugated with glycine and taurine. Lesser amounts of the amino acid conjugates of chenodeoxycholic acid, ursodeoxycholic acid, 7-ketodeoxycholic acid, allocholic acid, and deoxycholic acid, and of unconjugated norcholic acid and allonorcholic acid were also present in the bile. The major fecal bile acid was 7-epicholic acid. Relatively large amounts of bile acids were excreted in the urine. Unconjugated 7-epicholic acid, norcholic acid, allonorcholic acid, and cholic acid predominated. The bile acid profiles of the patient were different from those of normal subjects and should be useful for the diagnosis.

Bile acids. XLVII. 12alpha-Hydroxylation of precursors of allo bile acids by rabbit liver microsomes

Rabbit liver microsomal preparations fortified with 0.1 mM NADPH effectively promote hydroxylation of [3beta-3H]- or [24-14C]allochenodeoxycholic acid or [5alpha,6alpha-3H2]5alpha-cholestane-3alpha,7alpha-diol to their respective 12alpha-hydroxyl derivatives in yields of about 25 or 65% in 60 min. Minor amounts of other products are formed from the diol. The requirements for activity of rabbit liver microsomal 12alpha-hydroxylase resemble those of rat liver microsomes. Of a number of enzyme inhibitors studied only p-chloromercuribenzoate demonstrated a marked ability to inhibit the reaction with either tritiated substrate. There was no difference in the quantity of product produced from the tritiated acid or the 14C-labeled acid. No clear sex difference was found in activity of the enzyme, nor was an appreciable difference noted in activity of the enzyme between mature and immature animals.