Abstract

PIP: It was first determined that luteinizing hormone-releasing hormone (LH-RH) obtained from porcine, bovine, and ovine sources was biologically active in man. When the structure of porcine LH-RH was determined, synthetic material was also found active in man. Studies indicated that FSH as well as LH were released from the pituitary into the peripheral circulation by both the natural and synthetic LH-RH. Although blood basal levels of LH and FSH are increased after the menopause a further increase was produced by LH-RH, either naturally or synthetically. In other conditions (Klinefelter's and Turner's syndromes) with naturally occurring elevations of blood levels of LH and FSH, further release was also obtained by both natural and synthetic LH-RH. In subjects pretreated with 200 mg/day clomiphene additional rapid increase was obtained. In patients with pituitary tumors and acromegaly the response was variable. However, 1 patient who did not release gonadotropins after LH-RH did release thyrotropin (TSH) after receiving TSH-releasing hormone. The effects of LH-RH administration on other steroids in the blood are currently being investigated. Routes other than the intravenous administration are being tried, e.g., subcutaneous and intramuscular. It has been found that a child's pituitary can release LH and FSH after administration of porcine LH-RH. In Kallmann's syndrome of hypogonadotropic hypogonadism with anosmia, a small increase of gonadotropin release has been shown after rapid intravenous injection of LH-RH. Long duration of intravenous infusion of LH-RH with 2 supplementary intramuscular injections has produced ovulation in a patient primed with an FSH-containing material (Pergonal). In other experiments patients pretreated with clomiphene had an increased incidence of ovulation. In men with oligospermia only slight improvement has been obtained. Most of the data presented were obtained using highly purified material of porcine origin.