A specific substance P antagonist attenuates non-cholinergic electrically induced contractures of the guinea pig isolated ileum.
The substance P (SP) analog, D-Pro2,D-Tryp7,9-SP attenuated in a dose-dependent fashion non-cholinergic excitatory responses of the guinea pig ileum to the exogenous administration of SP, but did not affect the atropine-resistant contractures produced by serotonin (1 microM), histamine (1 microM), bradykinin (0.01 microM) or prostaglandin F2 alpha (10 microM). Pretreatment with D-Pro2,D-Tryp7,9-SP also significantly reduced the magnitude of the non-cholinergic contracture evoked by field stimulation at 20 Hz. These results suggest that enteric SP-containing neurons can function in an efferent motor capacity to bring about non-cholinergic excitation of the longitudinal muscle layer of the guinea pig small bowel.
D000818:Animals; D001920:Bradykinin / Q000008:administration & dosage; D015237:Dinoprost; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006168:Guinea Pigs; D006632:Histamine / Q000008:administration & dosage; D066298:In Vitro Techniques; D011460:Prostaglandins F / Q000008:administration & dosage; D012701:Serotonin / Q000008:administration & dosage; D013373:Substance P / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
D011460:Prostaglandins F; D012701:Serotonin; D013373:Substance P; C032132:substance P, prolyl(2)-tryptophan(7,9)-; D006632:Histamine; D015237:Dinoprost; D001920:Bradykinin