Abstract

PIP: Literature on luteinizing hormone-releasing hormone (LH-RH) and its analogues is reviewed. LH-RH, which stimulates the release of both luteinizing hormone (LH) and follicle stimulating hormone (FSH), is active in numerous species. It has been postulated that the release and synthesis of FSH and LH is mediated by an interaction between sex steroids and hypothalamic LH-RH. Administration of antiserum to LH-RH has been shown to block the preovulatory LH surge and ovulation in laboratory animals, which suggests an immunological approach to fertility control. It appears that LH-RH is rapidly broken down by dispersed liver, anterior pituitary, and kidney cells. Cyclic AMP has been shown to act as a mediator of LH-RH and FSH release. Although LH-RH has potential diagnostic value, its effectiveness in differentiating various types of hypogonadism is not clearly established. Generally, sex steroids diminsh the responses to LH-RH, though estrogens have both a stimulatory and inhibitory effect. Glucocorticoids have been shown to suppress the LH response to LH-RH. LH-RH has been effective in inducing ovulation in anovulatory women, and in treating men with hypogonadotropic hypogonadism. Stimulatory and inhibitory analogues of LH-RH and their clinical application are reviewed.