Hormonal Regulation of Spermatogenesis
The hypothalamus, the pituitary, and the testes form an integrated feedback system responsible for the correct secretion of male hormone and for normal spermatogenesis. The testes require stimulation by the pituitary gonadotropins, luteinizing hormone (LH), and follicle stimulation hormone (FSH), which are secreted in response to the pulsatile secretion of hypothalamic gonadotropin-releasing hormone (GnRH) [1, 2]. GnRH has a direct connection to the posterior lobe of the pituitary gland, and so it stimulates FSH and LH release by a direct apocrine effect. It is only permissive and does not participate in the feedback loop.