In vitro studies of human ovarian contractility

Human ovarian tissue was studied for in vitro contractility. Spontaneous contractions were recorded in each of the 28 ovaries. Ovarian contractility was not as pronounced as in the cat, rabbit, and monkey. No significant differcnces were recognized in contractile patterns of preovulatory, postovulatory, or postmenopausal ovaries, although postmenopausal ovarian contractions were characterized by low amplitude. Ovaries from the postovulatory phase were most sensitive to adrenergic agents. Postovulatory phase ovaries tended to be less responsive to prostaglandins than were preovulatory and postmenopausal ovaries. Oxytocin exerted a stimulatory effect, and its action did not vary with the phase of the cycle. The cholinergic agents, neostigmine and bethanechol, exerted a stimulatory effect, while atropine inhibited ovarian contractions. The tendency for ovaries to respond differently to specific substances at distinct times in the cycle supports the hypothesis that local hormonal environment influences ovarian contractility, which may be physiologically significant in the mechanism of ovulation.