Neurogenic relaxation mediated by vasoactive intestinal polypeptide (VIP) in the isthmus of the human fallopian tube

摘要: The smooth musculature of the Fallopian tube is important for normal ovum transport, fertilization and implantation. Little known about factors controlling motor activity isthmic sphincter. Studies were performed on muscle preparations from human in vitro. Electrical field stimulation nerves region reduced activity, particularly circular muscle. response was unaffected by adrenergic cholinergic antagonists, but blocked tetrodotoxin, suggesting a neural involvement. Vasoactive intestinal polypeptide (VIP) considered likely candidate mediation this view high density VIP-containing nerve fibres region, fact that exogenous VIP causes marked reduction tubal activity. To test whether might be endogenous mediator effect, carried out presence large amounts order to occupy all receptors; inhibitory action counteracted vasopressin. Under these conditions, failed reduce This not due vasopressin since occurred peptide alone. results suggest responsible neurogenic inhibition isthmus tube.