Modification of gonadotropin release after multiple or prolonged stimulation with synthetic LH-RH.

From previous research it is known that rapid iv injection of luteinizing hormone-releasing hormone (LH-RH) into amenorrheic patients will result in either 1) absent or deficient pituitary LH response 2) normal LH release or 3) an exaggerated response. The present study was conducted to elucidate the significance of these varying pituitary responses as they relate to the underlying causes of amenorrhea. The deficient response pattern found primarily in cases of primary amenorrhea could be "normalized" by multiple LH-RH stimulation but could not be sustained. Exaggerated responses could also be normalized in this manner lending support to the hypothesis that exaggerated responses result from low levels of endogenous LH-RH. In view of the inability to sustain normal LH output where response deficiency exists pituitary dysfunction must be suspected. Since acute LH-RH stimulation does not reveal this prolonged stimulation is necessary to distinguish pituitary hypofunction from that of higher centers.