What are the factors affects testosterone secretion?

The factors affecting testosterone can be categorized as autocrine, paracrine, endocrine and neuroendocrine. Autocrine. Androgens produced by the Leydig cells exert autocrine control on its own testosterone biosynthesis. Paracrine,

(i) Inhibin and estrogens produced by the Sertoli cells inhibit testosterone production by Leydig cells,

(ii) High intratubular testosterone levels are essential for normal spermatogenesis. Endocrine, (i) FSH is necessary for normal spermatogenesis. FSH promotes the synthesis of androgen-binding protein (ABP) by Sertoli cells. ABP binds testosterone, increasing its local concentration, which supports spermatogenesis, (ii) FSH indirectly affects testosterone synthesis by increasing the number of LH receptors on the Leydig cell, (

iii) GnRH controls testosterone secretion by stimulating the release of both LH and FSH from the anterior pituitary. GnRH secretion is pulsatile occurring at a frequency of 8 to 14 pulses per day. (iii) LH stimulates the Leydig cells and increases testosterone synthesis,

(iv) Insulin, prolactin and thyroxin have direct stimulatory effects on Leydig cells. Neuroendocrine. Opiates, neuropeptides and neurotransmitters affect GnRH secretion and thereby, the secretion of testosterone.