Noncholinergic contractile response to nicotine in the guinea pig isolated tracheal smooth muscle.
The existence of substance P immunoreactive nerves in the trachea of guinea pig is known. In this study, capsaicin induced a long-lasting and marked contraction in the guinea pig trachea and nicotine-induced contraction was partially reduced in the capsaicin-treated muscle. Furthermore, the contractile response to nicotine (10(-5) M) in the presence of atropine (10(-7) M) was abolished by a substance P antagonist, [D-Arg1, D-Pro2, D-Trp7,9 Leu11]substance P (10(-5) M). These findings suggest that noncholinergic contractile response to nicotine may be due to the release of material(s) resembling substance P in the isolated tracheal smooth muscle preparation of guinea pig.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001341:Autonomic Nervous System / Q000502:physiology*; D002211:Capsaicin / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D013373:Substance P / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects
D013373:Substance P; D009538:Nicotine; D001285:Atropine; D000109:Acetylcholine; D002211:Capsaicin