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.