Regulation of Gonadal Androgen Secretion

Abstract

The various mechanisms regulating testicular and ovarian androgen secretion are reviewed. Testicular androgen secretion is controlled by luteinizing hormone (LH) and follicle stimulating hormone (FSH), which influence the Leydig cell response to the LH. The contribution of prolactin, growth hormone and thyroid hormones to the Leydig cell function is discussed. The ovarian androgen secretion is regulated in a very similar fashion as the Leydig cell of the testis. Prolactin, however, has an inhibitory effect on androgen secretion in the ovary. The intratesticular action of androgens is linked to spermatogenesis. Sertoli cells, by producing the androgen-binding protein, contribute to the intratubular androgen concentration. Inhibin production of the Sertoli cell is stimulated by androgens. In the ovary, androgens produced by the theca interna are used as precursors for the aromatization of estradiol, which stimulates together with FSH the mitosis of granulosa cells. The feedback control of androgen secretion is complicated, as the direct feedback mechanisms are joined by indirect feedback regulations like the peptide inhibin, which can be stimulated by androgens. Intragonadal mechanisms regulating androgen production are the cybernins for testicles and ovaries. In the testicle, estrogens from the Sertoli cells regulate the Leydig cell testosterone biosynthesis. In the ovary, nonaromatizable androgens are potent inhibitors of the aromatization activity in the granulosa cell. A peptide with a FSH receptor binding inhibiting activity is found in male and female gonads. Finally, LH-RH-like peptides have been found in the testicle, which are capable of inhibiting steroidogenesis. These gonadocrinins are similarly produced in granulosa cells of the ovary.

Effects of Ramadhan Fast on Male Fertility

“…As FSH is responsible for the steroidogenesis in the testicular tissues, the variation of testosterone level may be related to the variation of FSH levels. This proportionate change of testosterone to FSH and LH hormonal changes confirms other reports [3]. Prolactin has an inhibitory effect on the testicular androgen production.…”

Impact of estrogens in males and androgens in females

“…Similarly to estrogen, testosterone is synthesized by both males and females, albeit in different quantities. Testosterone production by Leydig cells in the testes of males is 7 to 8 times higher than that produced by the ovaries in females (3). Testosterone is converted to dihydrotestosterone (DHT), and both of these bind the androgen receptor (AR), although DHT has a greater affinity and cannot be aromatized to estrogen.…”

Retinoic acid receptor beta and angiopoietin-like protein 1 are involved in the regulation of human androgen biosynthesis

“…However, it is known that the adrenocorticotropic hormone (ACTH) and its signaling network, which regulate glucocorticoid production in the zona fasciculata (ZF) of the adrenal cortex, play a co-regulatory role for androgen production 1 . By contrast, estrogen and testosterone production in the ovary and testis are regulated through the gonadotropin-releasing hormone (GnRH) of the hypothalamus and the luteinizing hormone (LH) and the follicle-stimulating hormone (FSH) of the pituitary gland 2 .…”