The role of gonadotrophin releasing hormone in the investigation and treatment of hypogonadism.

Normal progression through puberty and maintenance of fertility depends on the integral functioning of the hormonal circuit linking the hypothalamus, pituitary and gonads shown in Figure 1. The hypothalamic factor gonadotrophin-releasing hormone (Gn-RH) was isolated and its structure determined in 1971 (Schally et al., 1971). This releasing hormone acts on cells within the anterior pituitary and stimulates their secretion of the gonadotrophins, follicle stimulating hormone (FSH) and luteinizing hormone (LH). Gonadotrophin-releasing hormone is given for therapeutic as well as for diagnostic purposes and there is now considerable clinical experience of its use. This article discusses the clinical use ofGn-RH in the investigation and treatment of infertility and delayed puberty and the clinical application of the development of long-acting synthetic analogues.