The hypothalamic regulation of gonadotrophin secretion.
Episodic release of GnRH stimulates the gonadotrophs, causing pulsatile release of LH and, to a lesser extent, FSH. LH acts on Leydig cells causing the production of testosterone which is responsible for vinlisation (in some tissues through the production of dihydrotestosterone). LH release is suppressed by the negative feedback mechanism of the testosterone action on the hypothalamus and pituitary. FSH acts on Sertoli cells and this results in spermatogenesis. Inhibin has a negative feedback effect and activin has a positive effect on FSH production in the anterior pituitary.
