Reactivity of isolated trachea, bronchus and lung strip of cats of carbachol, 5-hydroxytryptamine and histamine: evidence for the existence of methysergide-sensitive receptors.
1 The reactivity was investigated of cat isolated tracheal chains, bronchial spirals and lung parenchymal strips to carbachol, 5-hydroxytryptamine (5-HT) and histamine. 2 Carbachol and 5-HT produced concentration-dependent contractions of all three tissues, responses to the former drug being selectively blocked by atropine and to the latter by methysergide. 3 Histamine failed to elicit a contractile response from the tracheal or bronchial muscle. However, it induced dose-related concentrations of the lung strips, that were selectively blocked by mepyramine. 4 It is concluded that lung parenchymal strips of cats possess mepyramine-sensitive histamine H1-receptors. Receptors for 5-HT, susceptible to methysergide, occur in the tracheobronchial smooth muscles as well as in lung strips of cats.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001980:Bronchi / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology*; D002415:Cats; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects; D008784:Methysergide / Q000494:pharmacology*; D011738:Pyrilamine / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology*; D014132:Trachea / Q000187:drug effects
D011985:Receptors, Serotonin; D012701:Serotonin; D001285:Atropine; D006632:Histamine; D002217:Carbachol; D011738:Pyrilamine; D008784:Methysergide