Abstract
The presence of small amounts of 3β-hydroxy-Δ5-C19- and C21-steroid oxidoreductase in the microsomal fraction of rat liver is shown. NAD was the preferred cofactor. Km for the oxidation of dehydroepiandrosterone (3β-hydroxy-5-androsten-17-one) into androstenedione (4-androstene-3,17-dione) was 3 × 10-6 M. In similarity to the adrenal and gonadal 3β-hydroxy-Δ5-C19-steroid oxidoreductase, but in contrast to the hepatic 3β-hydroxy-Δ5-C27-steroid oxidoreductase involved in the biosynthesis of bile acids, the hepatic 3β-hydroxy-Δ5-C19-steroid oxidoreductase was inhibited by the 3β-hydroxy-Δ5-steroid oxidoreductase inhibitor, 2α-cyano-4,4,17-trimethyl-17β-hydroxy-5-androsten-3-one, and the activity was greatly reduced with microsomes from immature rats.
Original language | English (US) |
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Pages (from-to) | 471-476 |
Number of pages | 6 |
Journal | Steroids |
Volume | 19 |
Issue number | 4 |
DOIs | |
State | Published - Apr 1972 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Endocrinology
- Pharmacology
- Clinical Biochemistry
- Organic Chemistry