Restoration of normal pituitary gonadotropin reserve by administration of luteinizing-hormone-releasing hormone in patients with hypogonadotropic hypogonadism.

To elucidate whether diminished pituitary gonadotropin reserve can be restored by repeated stimulation with luteinizing-hormone-releasing hormone, plasma luteinizing hormone and follicly-stimulating hormone responses were studied before and after daily intravenous infusion of 400 mug of luteinizing-hormone-releasing hormone for two to 23 days, in patients with hypogonadotropic hypogonadism of various causes. In five of nine patients with isolated gonadotropin deficiency, the impaired plasma luteinizing hormone response was restored to normal after treatment for seven days or more, whereas it was unchanged in four patients treated for less than five days. However, six patients with anorexia nervosa regained normal responses after three to five days' treatment. Five of nine patients with organic hypothalamopituitary lesions also showed normal responsiveness after five to seven days' treatment. These results suggest that the response to the test after repeated administration of luteinizing-hormone-releasing hormone is of value for the diagnosis of hypogonadism of hypothalamic origin.