Gonadotrophin synthesis

Mohabeer J, Buckley CH, Fox H. An immunohistochemical study of the incidence and significance of human chorionic gonadotrophin synthesis by epithelial ovatian neoplasms. Gynecol Oncol. 1983 16 78-84. 

Table 11.8 The gonadotrophins, their site of synthesis and their major biological effects...

The synthesis and release of both FSH and LH from the pituitary is stimulated by a hypothalamic peptide, gonadotrophin-releasing hormone (also known as gonadorelin, LH-releasing hormone, or LH/FSH-releasing factor). 

Figure 19.11 Hormones secreted by the hypothalamus, anterior pituitary, ovary and testis and feedback regulation. GnRH is gonadotrophin-releasing hormone the gonadotrophins are follicle-stimulating hormone (FSH) and luteinising hormone (LH). The effect of these hormones on activities in the ovary and testes is shown. FSH stimulates synthesis and secretion of oestradiol from follicle, and spermatogenesis in testis. LH stimulates synthesis and secretion of progesterone from corpus luteum and synthesis and secretion of testosterone by the Leydig cells.

Table 1.10. Some pharmaceutical substances originally isolated from animal sources. While some are still produced by direct extraction from the native source, others are now also produced by direct chemical synthesis (e.g. peptides and some steroids), or by recombinant DNA technology (most of the pol5 peptide products). Abbreviations hGH = human growth hormone FSH=follicle stimulating hormone hCG=human chorionic gonadotrophin HSA=human serum albumin HBsAg=hepatitis B surface antigen...

In the human female, IGF-1 is expressed by follicular theca cells, while IGF-2 is synthesized by granulosa cells (Chapter 8). The IGF-1 and -2 receptors are widely expressed in ovarian tissue, and synthesis of both growth factors and their receptors are influenced by circulating gonadotrophin levels. IGF-1 exerts a direct mitogenic effect on human granulosa cells, and promotes increased androgen and oestradiol synthesis by these cells. IGF-1 also promotes increased expression of FSH and LH receptors in ovarian tissue. 

The episodic secretion of the hypothalamic hormone, gonadotrophin-releasing hormone (GnRH), stimulates synthesis and release of the gonadotrophins. LH (luteinizing hormone) and FSH (follicle-stimulating hormone), from the anterior pituitary. Despite the names, both gontidotrophins act cooperatively on the ovaries in the woman and the testes in the man to stimulate sex hormone secretion and reproductive processes. 

GnRH acts directly on the adenohypophysis to stimulate the synthesis and release of both gonadotrophins [72—75]. It was originally postulated that separate hypothalamic hormones control the secretion of LH and FSH. However, attempts to isolate two such fractions from hypothalamic tissue have failed... 

Anti-ferti1i ty - The potential of steroids in the anti-fertility area is probably still the leading motivation for research in this field, but little new information has appeared. Two steroids, oxymetholone and nandrolone phenpropionate, both well established anabolic agents, were shown to cause resorption of fetuses after implantation. The term "Inter-ceptives" was proposed for this type of effect. This action of both compounds could be reversed by progesterone. It was postulated that oxymeth-olone suppresses pituitary gonadotrophin release, while nandrolone phenpropionate either inhibits luteal synthesis of progesterone or competitively blocks a uterine receptor site necessary for pregnancy maintenance. ... 

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