EFFECTS ON THE PERINEAL SWELLING AND ON THE MENSTRUAL CYCLE OF SINGLE INJECTIONS OF COMBINATIONS OF ESTRADIOL BENZOATE AND PROGESTERONE GIVEN TO BABOONS IN THE FIRST PART OF THE CYCLE1

Abstract

Inhibition of the ovary by combinations of estradiol and progesterone, simultaneously administered, is described. 5 mg. of estradiol benzoate and 20 mg. of progesterone caused the turgescent perineum to return to rest by the 9th to 10th day in 4 baboons; cystic follicles were present in the ovaries. In 1 animal bleeding was premature and the cycle was shortened. In 3 other animals the perineum began to swell again after the induced turgescence, and bleeding occurred in 2 on the 32nd day of the cycle while the perineum was still turgescent; in the remaining animal the cycle was prolonged by 12 days. Dosages of 5 mg. of estradiol benzoate and 10 mg. of progesterone lengthened the cycle by 17 days. Smaller dosages elicited a variety of responses but in general the cycle was shortened. Bleeding induced by 20 mg. of progesterone in the early cycle could be inhibited by simultaneous adm. of 5 mg. of estradiol benzoate. Ten mg. of progesterone together with 5 mg. of estradiol benzoate produced a result similar to that obtained with estradiol. In 3 of 4 animals injected with 5 mg. of estradiol benzoate and 20 mg. of progesterone cystic ovaries were induced within 24-34 days.