Neuronally mediated non-cholinergic contraction of guinea-pig bronchial smooth muscle is inhibited by a substance P antagonist.
The isolated main bronchi of the guinea-pig respond to electrical field stimulation with a twitch followed by a slow contraction. Atropine blocked the slow contraction. The substance P antagonist, (D-Pro2, D- Trp7 ,9)-SP, greatly reduced the atropine-resistant contraction. The results suggest the involvement of substance P in non-cholinergic neurotransmission in the guinea-pig airways.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001980:Bronchi / Q000294:innervation / Q000502:physiology*; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D013373:Substance P / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D013373:Substance P; D001285:Atropine; C032132:substance P, prolyl(2)-tryptophan(7,9)-