The effects of cholinergic agents on ovarian contractility in the rabbit

Cholinergic nerves have been recognized in the ovaries of several species. Smooth muscle fibers have also been demonstrated within the ovary, and it has been suggested that these elements are involved in the ovulatory process. Ovarian contractility was investigated in 49 ovaries from 25 rabbits in in vivo and in vitro systems and correlated with the time of hCG-induced ovulation. Effects of 6 cholinergic drugs on ovarian contractility were recorded at various intervals from 6 to 20 hours after administration of hCG. Cholinergic agents were administered via the abdominal aorta in the in vivo preparations and added to the bath for in vitro studies. In general, acetylcholine, bethanechol and pilocarpine exerted variable effects. Atropine depressed ovarian contractile activity. No definitive pattern of altered sensitivity to cholinergic drugs could be identified as the time of ovulation was approached; however, a relationship was observed between the amount of cholinergic drug administered and effects on ovarian contractions.