Gonadotrophin-releasing hormone.

Abstract

After the classic animal experiments of Harris (1950), Harris and Johnson (1950), and McCann and Dhariwal (1966) it was assumed that in man too the hypothalamus controlled the release of luteinising hormone (LH) and follicle-stimulating hormone (FSH) independently by means of two releasing hormones, luteinising hormone-releasing hormone (LH-RH) and follicle stimulating hormone-releasing hormone (FSH-RH). However, Schally et al. (1971) were ableto isolate only one gonadotrophin-releasing hormone from many thousands of porcine hypothalami. This hormone (GnRH), a decapeptide, stimulates the secretion of both LH and FSH in animals and in man and can produce differential changes in the secretion of the two gonadotrophins by interaction with the feedback effects of gonadal steroids and inhibin. The latter inhibits FSH secretion. It is probably a polypeptide and is formed in the seminiferous tubules during the final stage of spermatogenesis (which is itself stimulated by FSH).