title: Effects of the antiestrogen CI-628 on hCG-induced desensitization of testosterone in purified Leydig cells.
abstract: The effect of CI-628 on human chorionic gonadotropin-induced desensitization of testosterone production was investigated. Purified Leydig cells were isolated from mature male rats 24 hr postinjection with (1) 30 of 300 IU hCG s.c., (2) 1 mg CI-628 i.p., or (3) CI-628 pretreatment plus hCG. Steroidogenic desensitization to Bt2 cAMP and hCG stimulation in vitro was observed with both doses of hCG administered in vivo. CI-628 treatment alone led to an increased basal production but an unaltered maximum production of testosterone obtained in the presence of hCG or Bt2 cAMP in vitro. CI-628 in combination with hCG treatment in vivo led to testosterone production in vitro that was similar to that observed with hCG treatment alone. CI-628 does not inhibit the hCG-induced desensitization of testosterone production, and the results do not support a role of estrogen receptors in this process.
mesh_terms: D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology*; D066298:In Vitro Techniques; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009594:Nitromifene / Q000494:pharmacology*; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen / Q000502:physiology; D013267:Stilbenes / Q000494:pharmacology*; D013739:Testosterone / Q000096:biosynthesis*
chemical_list: D006063:Chorionic Gonadotropin; D004965:Estrogen Antagonists; D011759:Pyrrolidines; D011960:Receptors, Estrogen; D013267:Stilbenes; D013739:Testosterone; D009594:Nitromifene; D003994:Bucladesine; C029102:CI 628M