Affordable Access

Direct effect of androgens on progesterone binding and metabolism in rat testis microsomes.

Authors
  • Kühn-Velten, N
  • Bunse, T
  • Schürer, N
  • Staib, W
Type
Published Article
Journal
Hoppe-Seyler's Zeitschrift fur physiologische Chemie
Publication Date
Jul 01, 1984
Volume
365
Issue
7
Pages
773–779
Identifiers
PMID: 6090301
Source
Medline
Language
English
License
Unknown

Abstract

A possible site of action at which androgens may control their own biosynthesis in rat testicular tissue in terms of an intratesticular feedback mechanism is investigated. It is shown that both progesterone (Ks = 0.45 microM) and testosterone (Ks = 14.7 microM) induce spectral changes at microsomal cytochrome P-450; these spectral effects are not additive and therefore both steroids may act on the same species of cytochrome P-450. This hypothesis is supported by the observation of competitive inhibition by testosterone of progesterone binding to solubilized microsomal proteins (Ki = 10.0 microM) and of progesterone conversion to androgens (Ki = 14.3 microM). It is concluded that rat testicular androgen biosynthesis is subject to feedback regulation not only via the pituitary-testicular axis but also by direct action of androgens on microsomal reactions dependent on progesterone-binding cytochrome P-450.

Report this publication

Statistics

Seen <100 times