Correlation between integrated LH and FSH levels and the response to luteinizing hormone relasing factor (LRF)

Abstract

Integrated blood plasma levels of LH and FSH and their response to the iv administration of 100 mug synthetic LRF were studied in 29 normal subjects, 12 women with Stein-Leventhal syndrome, 8 subjects with primary gonadal failure, 7 women with Sheehan's syndrome, 20 subjects with pituitary tumors, 10 subjects with idiopathic gonadotropin deficiency and 5 subjects with hypothalamic tumors. Within each group there was considerable variation in the response of LH and FSH levels to LRF. In each group there was a statistically significant positive correlation between basal integrated gonadotropin levels and the response of the levels to LRF. Both within groups and between groups, the best indicator of the response to LRF was the basal levels of FSH and LH. In subjects with hypogonadotropic hypogonadism there was no significant difference in mean basal LH levels and mean response to LRF between patients with primarily pituitary disease (pituitary tumors or Sheehan's syndrome) and conditions which might represent hypothalamic disease (hypothalamic tumors or idiopathic gonadotropin deficiency). The response to an acute, single, injection of LRF appears to more directly reflect basal gonadotropin levels rather than disease category.

PIP: The diagnostic value of LRF was assessed by measuring the response of plasma levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) to a single iv injection of synthetic LRF in 29 normal subjects, 12 women with Stein-Leventhal syndrome, 8 patients with primary gonadal failure, 7 women with Sheehan's syndrome, 20 patients with pituitary tumors, 10 subjects with idiopathic gonadotropin deficiency, and 5 patients with hypothalamic tumors. The response of plasma LH and FSH levels to LRF varied considerably within each group. Each group showed a positive correlation between basal LH and FSH levels and the response to LRF. There was no marked difference in basal LH values and the mean response to LRF between patients with pituitary tumors of Sheehan's syndrome and patients with hypothalamic tumors or idopathic gonadotropin deficiency. It is concluded that the response to a single, acute iv injection of LRF provides little information of disease states beyond that provided by basal gonadotropin levels.