Release of LH and FSH after Administration of Synthetic LH-Releasing Hormone*

Abstract

Synthetic (pyro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂, identical in structure with natural LH-releasing hormone (LHRH), was tested in the human being. This synthetic decapeptide was injected iv into three untreated men, two untreated women, three men pretreated with ethinyl estradiol, and three women pretreated with an oral contraceptive (Lyndiol). LH-RH caused a marked increase in plasma LH levels (p < 0.01) and a smaller, but significant p < 0.01) increase in plasma FSH levels. The elevated LH and FSH values after administration of LH-RH did not differ among the groups, although individual variation was large. Since synthetic (pyro) Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂ stimulates the release of LH and FSH in man and can be made in large quantities, many clinical studies are now possible.