The frequency of pulsatile luteinizing hormone-releasing hormone treatment and luteinizing hormone and follicle-stimulating hormone secretion in women with amenorrhea of suprapituitary origin**Supported by a grant from the Foundation for Medical Research (MEDIGON), which is subsidized by the Netherlands Organization for the Advancement of Pure Research (ZWO).††Presented in part at the Sixth Reinier de Graaf Symposium, Nijmegen, The Netherlands, August 27 to 29, 1987.

The influence of luteinizing hormone-releasing hormone (LH-RH) pulse frequency on luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was studied in hypogonadotropic hypogonadal women. They received three regimens of 5 days of pulsatile LH-RH (5 μg/pulse) given at 30-, 90-, or 180-minute intervals, with at least 6 weeks between treatments. On day 1, LH and FSH increased in proportion to the LH-RH pulse frequency. After 5 days of treatment with the 30- and 90-minute intervals, LH was still elevated, but FSH had returned to pretreatment levels together with a decline of the FSH response. The LH response only declined during treatment with the 30-minute pulse interval. During each treatment, estradiol (E2) increased. Explanations for dissociation between LH and FSH secretion during treatment with higher LH-RH pulse frequencies could be: (1) desensitization of FSH rather than LH secretion on LH-RH; (2) a differential effect of E2on LH and FSH; (3) nonsteroidal ovarian factors selectively regulating LH and/or FSH release.