title: Regulation of 5 alpha-reductase activity in cultured immature leydig cells by human chorionic gonadotropin.
abstract: The present studies examined the hormonal regulation of 5 alpha-reductase activity in cultured immature rat Leydig cells. Within the testis 5 alpha-reductase was concentrated in the interstitial cell compartment, and among interstitial cells, the enzyme was localized primarily in Band 3 of Percoll density gradients, which contains the majority of Leydig cells. Among various factors reported previously to stimulate testicular 5 alpha-reductase activity when administered in vivo to immature rats (LH/hCG, FSH, luteinizing hormone releasing hormone or prolactin), only LH/hCG directly stimulated 5 alpha-reductase activity of cultured immature Band 3 cells. Neither growth hormone which was reported previously to stimulate hepatic 5 alpha-reductase activity, nor insulin, insulin-like growth factor-I, or epidermal growth factor, which have been reported to modulate Leydig cell function, had any effect on 5 alpha-reductase activity of Band 3 cells. These studies suggest that the major factor directly stimulating 5 alpha-reductase activity in Leydig cells during early maturation is LH. However, it is possible that other factors acting indirectly may modulate the maturational rise in 5 alpha-reductase activity.
authors.affiliation: Research Service, WJBD Veterans' Hospital, Columbia, SC.
authors.forename: E P
authors.initials: EP
authors.lastname: Murono
authors.forename: A L
authors.initials: AL
authors.lastname: Washburn
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D001378:Azasteroids; D002478:Cells, Cultured; D042944:Cholestenone 5 alpha-Reductase; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D007985:Leydig Cells / Q000187:drug effects / Q000201:enzymology*; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011278:Pregnanes / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000201:enzymology / Q000254:growth & development; D013739:Testosterone / Q000378:metabolism
chemical_list: D001378:Azasteroids; D006063:Chorionic Gonadotropin; D006133:Growth Substances; D011278:Pregnanes; D013739:Testosterone; D007986:Luteinizing Hormone; C037399:4-methyl-4-aza-3-oxopregnane-20-carboxylate; D010088:Oxidoreductases; D015096:3-Hydroxysteroid Dehydrogenases; C031954:delta(5)-3 beta-hydroxysteroid dehydrogenase; D042944:Cholestenone 5 alpha-Reductase