The control of FSH secretion involves peptide and steroid hormones. Serum FSH levels increase as germinal elements in the testis are lost, whereas there is a minimal change in LH levels. Inhibin, an inhibitor of pituitary FSH secretion, is formed in Sertoli cells. It is a glycoprotein that consists of two disulphide-linked subunits ΓÇô alpha combined with bA or bB Both FSH and androgen control normal inhibin production. Combinations of the b-subunits of inhibin into homodimers or heterodimers, termed activins, in contrast to inhibin stimulate FSH release from the pituitary.
