luteinizing hormone in androgen production
Last reviewed 01/2018
LH acts on interstitial Leydig cells to increase the flux generating step of cholesterol conversion to pregnenolone and thence testosterone.
LH secretion is dependent upon:
- GnRH released from the hypothalamus
- negative feedback from testosterone on:
- the anterior pituitary gonadodotrophin-synthesizing cells
- the hypothalamic GnRH-releasing cells
The feedback loops are used therapeutically in advanced androgen-sensitive prostatic carcinoma:
- GnRH analogues e.g. buserelin:
- these are given in high dose, eventually resulting in down-regulation of GnRH receptors on pituitary gonadotroph cells
- LH and FSH secretion is secondarily reduced
- testosterone secretion is reduced secondary to gonadotroph reduction
- testosterone antagonists e.g. cyproterone:
- limits initial stimulation of prostate by GnRH analogues
- cyproterone also acts centrally to inhibit GnRH secretion