Correlation Between Luteinizing Hormone Responses to Luteinizing Hormone-Releasing Hormone (LH-RH) And to d-Leu-6-LH-RH-Ethylamide in Patients with Hypothalamo-Pituitary Disease

Seventeen patients (eleven females and six males) with organic hypothalamopituitary disease were subjected to a test consisting of a rapid intravenous injection of 50 μg of luteinizing hormone-releasing hormone (LH-RH) at 8:00 A.M., with blood sampling before and 30 and 60 minutes afterward. Two to four weeks later, a rapid intravenous injection of 50 μg of d-Leu-6-des-Gly-10-LH-RH-ethylamide (d-Leu-6-LH-RH-EA) was given under similar conditions, with blood sampling before and 30, 60, and 90 minutes afterward. Serum LH levels were determined by radioimmunoassay. d-Leu-6-LH-RH-EA caused a greater and more sustained rise in serum LH levels than did an equal dose of LH-RH. However, functional classifications of patients were similar with either preparation. This finding suggests that acute administration of d-Leu-6-LH-RH-EA does not cause a higher number of relevant responses as compared with LH-RH, but only a greater stimulation of LH release in responsive patients.