Steroid 5α-Reductases and 3α-Hydroxysteroid Dehydrogenases: Key Enzymes in Androgen Metabolism

March 2001 in “ Baillière's best practice and research in clinical endocrinology and metabolism/Baillière's best practice & research. Clinical endocrinology & metabolism ”

Yi Jin, T.M. Penning

steroid 5α-reductases 5α-R 3α-hydroxysteroid dehydrogenases 3α-HSD androgen metabolism testosterone 5α-dihydrotestosterone 5α-DHT 3α-androstanediol androgen receptor gene transcription type 1 5α-R type 2 5α-R androgen-dependent diseases 5α-reductases 3α-HSD DHT androgen receptor

TLDR Key enzymes control androgen levels, affecting hormone activity and potential treatments.

The document discussed the roles of steroid 5α-reductases (5α-R) and 3α-hydroxysteroid dehydrogenases (3α-HSD) in androgen metabolism. In androgen target tissues like the prostate, type 2 5α-R converts testosterone to the potent androgen 5α-dihydrotestosterone (5α-DHT), which is then inactivated by reductive 3α-HSD to form the weaker androgen 3α-androstanediol. Conversely, oxidative 3α-HSD can regenerate 5α-DHT from 3α-androstanediol. These enzymes regulate the availability of androgens for the androgen receptor, influencing gene transcription. In peripheral tissues such as the liver, type 1 5α-R and reductive 3α-HSD work together to eliminate excess androgens. The distinct roles of these enzyme isoforms in anabolic and catabolic processes make them potential drug targets for treating androgen-dependent diseases.

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