title: Specific reductive metabolism of steroid sulphates in rat liver.
abstract: The reductive metabolism of steroid sulphates and corresponding unconjugated steroids has been investigated in male and female rat liver. Enzyme activities studied were 5alpha-reductase, 5beta-reductase and 3alpha-, 3beta- and 20beta-hydroxy-steroid oxidoreductases in microsomal and soluble cellular fractions. With the exception of microsomal 3alpha-reductase all enzymes were equally or more active using sulphoconjugated substrates than using corresponding unconjugated substrates. 20beta-reduction of corticosterone and deoxycorticosterone occurred only with the 21-sulphurylated derivatives. This sulphate-specific 20beta-reductase, which is only present in male rat liver, probably participates in the formation of the sex-specific 20beta-reduced corticosterone metabolites present in bile from male but not from female rats. Sulphoconjugated deoxycorticosterone and corticosterone were also better substrates for microsomal 5alpha-reductase and sulphoconjugated 5alpha-dihydrotestosterone for microsomal 3beta-hydroxysteroid oxidoreductase than the corresponding unconjugated analogues. In conclusion, these results indicate that steroid sulphates generally are good substrates for hepatic reducing enzymes; in many cases even better substrates than the unconjugated analogues.
mesh_terms: D000818:Animals; D005260:Female; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D012737:Sex Factors; D013256:Steroids / Q000378:metabolism*; D013464:Sulfuric Acids / Q000378:metabolism
chemical_list: D013256:Steroids; D013464:Sulfuric Acids; D006913:Hydroxysteroid Dehydrogenases