title: Blockade of electrical field stimulation-induced nonadrenergic noncholinergic (NANC) excitatory response of the guinea pig ileum.
abstract: Determination of guinea pig ileal response to electrical field stimulation (EFS) before and after complete adrenergic and cholinergic blockade showed that the nonadrenergic noncholinergic excitatory (NANC-e) response contributed 40% to the total contractile response. NANC-e responses were reproducible to consecutive identical EFS. Tetrodotoxin significantly blocked the NANC-e response. The NANC-e responses obtained before and after treatment of the tissues with receptor antagonists of histamine (pyrilamine), substance P ([D-Arg1,D-Pro2,D-Trp7,9,Leu11]-SP) and serotonin (5-HT1 & 5-HT2) indicated that the response could be blocked by substance P and serotonin antagonists. Only the serotonin antagonist cyproheptadine produced a dose-dependent blockade. Both substance P and serotonin are suggested to play an important role in the NANC-e neurotransmission.
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D007082:Ileum / Q000294:innervation*; D008297:Male; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D017981:Receptors, Neurotransmitter; D011994:Recombinant Proteins; D012702:Serotonin Antagonists / Q000494:pharmacology; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D006634:Histamine H1 Antagonists; D017981:Receptors, Neurotransmitter; D011994:Recombinant Proteins; D012702:Serotonin Antagonists; D013373:Substance P; C050702:substance P, Arg(1)-Pro(2)-Trp(7,9)-Leu(11)-