|Bile acids. XLVII. 12alpha-Hydroxylation of precursors of allo bile acids by rabbit liver microsomes.
|Year of Publication
|Ali SS, Elliott WH
|Biochim Biophys Acta
|1975 Nov 21
|Aging, Animals, Bile Acids and Salts, Female, Kinetics, Male, Microsomes, Liver, Mixed Function Oxygenases, NADP, Oxidation-Reduction, Rabbits, Sex Factors
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.
|Biochim. Biophys. Acta