Tachykinins play a minor role in mediating the third phase of the contractile response to vagal nerve stimulation of the guinea-pig oesophagus.
The aim of this study was to determine whether tachykinin receptors might be involved in the mediation of the atropine- and capsaicin-sensitive third phase of a triphasic contractile response to vagal nerve stimulation of the guinea-pig isolated oesophagus. The third phase was inhibited 23.3 +/- 1.7% (P< 0.001, n = 5) and 30. 8 +/- 9.0% (P< 0.05, n = 5) by the NK(3)receptor antagonist, SR 142 801 (0.1 and 1 microM respectively). SR 142 801 (0.1 and 1 microM) had no significant effect on the response to a submaximal concentration of acetylcholine (0.1 mM, n = 4). The third phase was not significantly affected by NK(1)or NK(2)receptor antagonists. Thus, in the guinea-pig oesophagus, it appears that while NK(1)and NK(2)receptors are not involved, NK(3)receptors play a minor role in mediating a contractile response when afferent neurones are excited by vagal nerve stimulation.
Kerr
K P
KP
Department of Pharmaceutical Biology and Pharmacology, Monash University, Victorian College of Pharmacy, Victoria, Australia. karen.kerr@vcp.monash.edu.au
Mitchelson
F
F
Coupar
I M
IM
D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D004558:Electric Stimulation; D004947:Esophagus / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D054833:Isoindoles; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines / Q000494:pharmacology; D011812:Quinuclidines / Q000494:pharmacology; D018040:Receptors, Neurokinin-1 / Q000502:physiology; D018041:Receptors, Neurokinin-2 / Q000037:antagonists & inhibitors / Q000502:physiology*; D018042:Receptors, Neurokinin-3 / Q000037:antagonists & inhibitors / Q000502:physiology*; D018039:Receptors, Tachykinin / Q000037:antagonists & inhibitors / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology*
D001549:Benzamides; D007211:Indoles; D054833:Isoindoles; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines; D011812:Quinuclidines; D018040:Receptors, Neurokinin-1; D018041:Receptors, Neurokinin-2; D018042:Receptors, Neurokinin-3; D018039:Receptors, Tachykinin; C071693:7,7-diphenyl-2-(1-imino-2-(2-methoxyphenyl)ethyl)perhydroisoindol-4-one; C085215:SR 140333; C089835:RPR 100893; C073839:SR 48968; C091554:SR 142801