Question

Explain the hormonal regulation of the process of spermatogenesis in humans.

Answer 1

• In humans the mechanism is not completely understood; however, it is known that the initiation of spermatogenesis occurs at puberty due to the interaction of the hypothalamus, pituitary gland, and Leydig cells. If the pituitary gland is removed, spermatogenesis can still be initiated by follicle stimulating hormone (FSH) and testosterone.
  
• FSH stimulates both the production of androgen-binding protein (ABP) by Sertoli cells and the formation of the blood-testis barrier. ABP is essential to concentrating testosterone in levels high enough to initiate and maintain spermatogenesis.
  
• Intratesticular testosterone levels are 20–100 or 50–200 times higher than the concentration found in blood, although there is variation over a 5- to 10-fold range amongst healthy men.