title: Evidence for vasoactive intestinal polypeptide as a neurotransmitter in smooth muscle of the urogenital tract.
abstract: The localization of vasoactive intestinal polypeptide (VIP) in the anococcygeus muscle of the rat, rabbit and cat was investigated by radioimmunoassay and immunohistochemistry. High concentrations of VIP-like immunoreactivity were found in the anococcygeus muscle of all 3 species. VIP-like immunoreactivity was observed in a network of nerve fibres branching throughout the muscle which were unaffected by treatment with 6-hydroxydopamine. VIP, when applied exogenously to isolated preparations of the anococcygeus, produced dose-related relaxations of tone in all 3 species with a time course and maximum response similar to non-adrenergic, non-cholinergic inhibitory nerve stimulation. These observations provide further evidence in support of VIP as a suitable candidate for the non-adrenergic, non-cholinergic inhibitory neurotransmitter in the anococcygeus muscle.
mesh_terms: D001003:Anal Canal; D000818:Animals; D002415:Cats; D005260:Female; D007124:Immunoenzyme Techniques; D008297:Male; D009130:Muscle, Smooth / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000032:analysis*; D010413:Penis; D011817:Rabbits; D051381:Rats; D013045:Species Specificity; D014660:Vasoactive Intestinal Peptide / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D018377:Neurotransmitter Agents; D014660:Vasoactive Intestinal Peptide