title: Studies on the kinetics of the interaction of 7 alpha-hydroxytestosterone with the steroid 5 alpha-reductase.
abstract: Microsomal preparations from adult male rat testicular interstitial cells were incubated with tritiated testosterone. Added 7 alpha-hydroxytestosterone, (7 alpha,17 beta-dihydroxy-4-androsten-3-one), at levels which appear to exist in the adult testis, inhibited production of labelled 5 alpha-reduced steroids in a graded fashion. This interaction is not competitive and occurs only at high substrate levels, such as those found in steroid-producing organs. Relationships to pubertal changes in steroid metabolism are discussed.
mesh_terms: D058891:5-alpha Reductase Inhibitors; D000818:Animals; D006915:Hydroxytestosterones / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000201:enzymology; D013739:Testosterone / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D058891:5-alpha Reductase Inhibitors; D006915:Hydroxytestosterones; C032278:4,17 beta-dihydroxy-4-androstene-3-one; D013739:Testosterone