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

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.