On the command of ICSH (interstitial cells stimulating harmone) or LH (leydig cells stimulating harmone) which reaches the seminiferous tubules and cause spermatogenesis. In this sertoli cells are present which have androgen binding protein to increase the concentration level of testosterone and on the command of FSH (follicle stimulating harmone), sertoli cells secrate nutrition so as to nourish the spermatocytes during the process of spermatogenesi, acting as nurse cells .It has a self-inhibiting protein INHIBIN which regulate (inhibit) secretion of FSH. It is also secreted by granulosa cells in females and have same function ( to inhibit the production of FSH) ...
