The influence of locally administered prostaglandin E2 and F2alpha on uterine motility in the intact non-pregnant human uterus.

Clinical studies on the effect of locally administered prostaglandin E2 and F2alpha on the sensitivity and reactivity of the non-pregnant human uterus were performed in 16 volunteers. With the use of the flaccid microballoon technique, uterine recordings were made at frequent intervals throughout the menstrual cycle. As little as 0.25 microgram PGF2 or 1.0 microgram PGF2alpha effected an increase in uterine motility during most of the proliferative and secretory phases of the menstrual cycle. However, a marked decrease in sensitivity and suppression of reactivity to either prostaglandin compound was observed around ovulation. Moreover, an inhibition of uterine contractility in response to PGE2 but not to PGF2alpha was noted during active menstrual bleeding. Circulating levels of estrogen could be correlated generally with these uterine responses. Endogenous prostaglandins normally occur in the secretory endometrium in levels compatible with the amount of exogenously administered prostaglandins which elicited increased, decreased, or unchanged uterine activity in this study. These findings suggest that local prostaglandin E2 and F2alpha in concert with variable levels of circulating estrogen, may play important roles in the cyclic regulation of uterine motility during the menstrual cycle.