Influence of estrogen and progesterone treatment on ovarian contractility in the monkey.

Five female rhesus monkeys were treated with natural estrogens, 5 mg/day for three weeks, after which ovarian contractility was studied in vitro in one of the ovaries. Estrogen treatment was followed by progesterone, 25 mg/day for three weeks, after which the contractility of the remaining ovary was similarly measured. Responses to autonomic agents and prostaglandins were studied in both groups. Spontaneous ovarian contractility and ovarian contractile responsiveness to prostaglandins and norepinephrine were found to be enhanced after progesterone treatment. Cholinergic agonists had a stimulatory effect after progesterone and an inhibitory effect after estrogens. Our results suggest that ovarian contractile responsiveness is modified by the local steroid environment, perhaps through intracellular changes in cyclic AMP.