Enhancement of isolated airway responses to bronchoconstrictive agonists by the slow-reacting substance of anaphylaxis antagonist FPL 55712.
The activity of the SRS-A antagonist FPL 55712 against histamine, carbachol and ion-induced contraction of isolated airway smooth muscle was evaluated. FPL 55712 enhanced responses of guinea-pig trachea and parenchymal lung strips to histamine and carbachol. Enhancement was not obviously related to concentration. It is suggested that this effect may be the result of cyclo-oxygenase inhibition by FPL 55712. These observations may account for some of the anomalous findings regarding the antagonism of leukotrienes by FPL 55712 previously reported.
D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002867:Chromones / Q000494:pharmacology*; D004987:Ethers / Q000494:pharmacology; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D012137:Respiratory System / Q000187:drug effects*; D013189:SRS-A / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects
D001095:Arachidonic Acids; D002867:Chromones; D004987:Ethers; D013189:SRS-A; D006632:Histamine; C006312:FPL 55712; D002217:Carbachol