Evidence for a Sertoli cell, FSH-suppressible inhibiting factor(s) of testicular steroidogenic activity.
By using a model of immature porcine Leydig and Sertoli cells cultured in serum free defined medium, we evidenced a paracrine control of Leydig cell steroidogenic activity by Sertoli cells via a secreted inhibiting protein(s). This protein(s), partially purified using gel filtration (M.W. 20,000-30,000) suppresses the steroidogenic responsiveness to LH/hCG by decreasing the specific LH/hCG binding (52% decrease) and hormone steroid biosynthesis (73% decrease) at a level(s) located between cAMP production and pregnenolone formation. The suppression of this inhibitor(s) by FSH, in a dose dependent manner, is one mechanism by which FSH "sensitizes" Leydig cell response to LH/hCG stimulation.
D000818:Animals; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D003470:Culture Media; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D011506:Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D012708:Sertoli Cells / Q000032:analysis*; D013552:Swine; D013739:Testosterone / Q000096:biosynthesis*
D006063:Chorionic Gonadotropin; D003470:Culture Media; D011506:Proteins; D013739:Testosterone; D005640:Follicle Stimulating Hormone