Vasoactive intestinal polypeptide (VIP) inhibits neurally evoked smooth muscle activity of rat uterine cervix in vitro

VIP inhibits the spontaneous motor activity (including tone) in isolated preparations of uterine cervix from oophorectomized rats, but has no direct effect on preparations from estrogen-treated animals. Electrical field stimulation of nerves in the tissue evokes a contractile response that is inhibited by VIP in a concentration-dependent manner. The neuronal link probably involves a cholinergic mechanism, since the contraction is blocked by atropine. The results suggest the presence of VIP receptors both in cholinergic nerves and in smooth muscle cells of the rat uterine cervix.