THE EFFECT OF LUTEINIZING HORMONE-RELEASING HORMONE IN HYPOGONADOTROPHIC EUNUCHOIDISM

Abstract

Fourteen patients with hypogonadotrophic eunuchoidism (HE), 10 males and 4 females, received luteinizing hormone-releasing hormone (LH-RH) as 4 h i.v. infusions of 0.2 .mu.g/min or as (s.c.) injections of 200 .mu.g. Repeated LH-RH administration over 4 days (200 .mu.g s.c. daily) was undertaken in 8 patients. Eight of the 10 males and all 4 of the females had definite elevations of luteinizing hormone (LH) and follicle stimulating hormone (FSH) following their 1st exposure to exogenous LH-RH. The patients included 2 males and 1 female with variant forms of HE, all of whom showed responses of both gonadotropins. When the 1st exposure of HE patients to exogenous LH-RH was as a 4 h infusion, the biphasic pattern of LH increase characteristic of normal adults was not found. Instead, a monophasic and qualitatively small LH increase occurred, similar to that found in pre-pubertal children and in anorexia nervosa. In 2 patients with an initially abnormal LH response, a 4 h LH-RH infusion following 4 days of LH-RH injections (200 .mu.g s.c./day) produced a normal biphasic LH increase. These results imply that maintenance of the 2 pools of pituitary LH demonstrable in normal adults depends on adequate production of endogenous LH-RH. Increases in FSH following the initial exposure to LH-RH were generally as great or greater than those of normal adults in spite of the fact that LH responses tended to be smaller than those of adults. Four days of LH-RH administration (200 s.c. daily) did not lead to consistent increases in gonadotropin responsiveness. Increases of testosterone or estradiol production could not be demonstrated, even with 4 to 5 days of LH-RH administration. Exogenous sex hormone therapy markedly inhibited gonadotropin responsiveness to LH-RH.