title: Tachykinin-mediated increase in motility acts independently of vasoactive intestinal polypeptide release in the canine ileum.
abstract: Tachykinins induce motor activity in the canine ileum, and their mechanism of excitation may include inhibition of the release of a nonadrenergic, noncholinergic inhibitor, for which vasoactive intestinal polypeptide (VIP) is a candidate. Both substance P and neurokinin A produced a dose-dependent increase in ileal contractility with no significant change in VIP output. The highly selective NK1 agonist [Sar9, Met(O2)11]substance P and the highly selective NK2 agonist [Nle10]neurokinin A (4-10) also increased motor activity in the absence of any change in VIP released. These data suggest that the tachykinins produce motor activity in the canine ileum via a mechanism that does not involve changes in VIP output but may involve excitation through both NK1 and NK2 receptors.
authors.affiliation: Department of Biomedical Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: E G
authors.initials: EG
authors.lastname: Watson
authors.forename: J E
authors.initials: JE
authors.lastname: Fox-Threlkeld
authors.forename: E E
authors.initials: EE
authors.lastname: Daniel
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D008297:Male; D015288:Neurokinin A / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D010446:Peptide Fragments / Q000494:pharmacology; D018040:Receptors, Neurokinin-1 / Q000187:drug effects; D018041:Receptors, Neurokinin-2 / Q000187:drug effects; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism / Q000502:physiology*
chemical_list: D010446:Peptide Fragments; D018040:Receptors, Neurokinin-1; D018041:Receptors, Neurokinin-2; C061060:neurokinin A (4-10), Nle(10)-; C062618:substance P, Sar(9)-Met(O2)(11)-; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D015288:Neurokinin A