Episodic secretion of LH and FSH after ovariectomy: Secretory patterns in response to estrogen and progesterone

Scrum LH antd FSH levels were studied at 20-minute intervals in 5 oophorectomized patients over 3 consecutive study days. Periodic oscillations were noted in LH levels in all patients and in FSH levels in 2 of 5 subjects during a control period. Estradiol, administered intravenously, led to a decline in LH levels in all 5 subjects. Fluctuations were still detectable in 4 women. Decreases in FSH levels were found in 3 women during the administration of estradiol. Progesterone was associated with a decline in LH in 3 patients and an increase in 1. Progesterone bad no effect on FSH levels. Episodic levels of gonadotrophins could be observed even during the administration of steroid. The sequence in which estrogen and progesterone were administered influenced serum gonadotrophin patterns.