Clinical studies with d-TRP6-luteinizing hormone-releasing hormone in men with hypogonadotropic hypogonadism

Three male patients, diagnosed to have hypogonadotopic hypogonadism, were treated with intramuscular injections of 10 microgram of D-Trp6-luteinizing hormone-releasing hormone (D-Trp6-LH-RH) every 8 hours for more than 90 days (13 to 17 weeks). The gonadotropin and testosterone concentrations reached levels twice as great during the treatment as those measured previously and on one occasion increased 5-fold. Before treatment, the patients were clinically in grade 1 on Tanner's scale (Growth at Adolescence, Second Edition. Oxford, Blackwell Scientific Publications, 1962) but after treatment they advanced to grades 2 to 4. Testicular sizes before treatment were between 2 and 2 according to the scales of Waaler et al. (Acta Paediatr Scand [Suppl]249:1, 1974) and afterwards between 4 and 10. The penis of one of the patients grew 3 cm. The testicular biopsy after treatment showed significant increases in the number of Leydig and Sertoli cells. After treatment, spermatogonia were present in increased number, together with a much higher population of cells corresponding to additional stages of development (spermatids). We are of the opinion that therapy with D-Trp6-LH-RH may be beneficial for such patients.