Effects of Estrogen and Progesterone on Pituitary Response to Stimulation by Luteinizing Hormone-Releasing Factor

Synthetic LRF in a dose of 150 μg was injected intravenously on two successive days in eight women with secondary amenorrhea. Two of the women received LRF injections only, three were treated with estradiol benzoate (EB) and three were treated with aqueous progesterone (P), each steroid being administered four hours after the start of the first test. Pre-treatment with both steroids had a marked suppressive effect on the magnitude of the pituitary response to exogenous LRF in the second test. The results, suggest a direct effect of ovarian steroids on pituitary gonadotropin producing cells.