LUTEINIZING-HORMONE (LH) PULSATILITY DURING THE ESTRADIOL-INDUCED ANDESTRADIOL PROGESTERONE-INDUCED LH SURGE IN THE HUMAN FEMALE

Positive feedback reactions were induced in rive female volunteers wit h regular menstrual cycles on the pituitary secretion of luteinizing h ormone (LH) during the follicular phase of the cycle by the i.m. admin istration of oestradiol benzoate ('oestradiol study'), or by oestradio l benzoate followed by progesterone ('oestradiol/progesterone study'). Prior to the administration of the steroids (basal profiles) and duri ng the LH surges following the administration of the steroids (stimula tion profiles), blood was drawn at 10-min intervals and the LH pulsati lity assessed. The LH pulses occurred at hourly intervals in basal and stimulation profiles, which concurs with data obtained during the nor mal proliferative phase and the spontaneous mid-cycle surge of the cyc le in both the human and the rhesus monkey. Our findings are, however, in sharp contrast with those obtained in the rhesus monkey by the det ermination of hypothalamic multi-unit activity.