Beta-adrenoceptor and cyclo-oxygenase block as a tool for evoking the direct bronchoconstrictor effect of leukotriene C4 in the guinea-pig.
The intravenous administration of LTC4 to anaesthetized guinea-pigs induced dose-dependent bronchoconstriction, which was maximal at the dose of 1.6 nmol kg-1. The response was abolished by indomethacin. The maximal dose of LTC4, preceded by both (-)-propranolol and indomethacin, induced maximal, slow in onset and reversible broncho-constriction. This direct effect of LTC4 was markedly and long-lastingly antagonized by FPL-55712. The beta-blocker did not appreciably affect the systemic blood pressure changes induced by LTC4. The procedure described is suggested as a suitable tool for investigating the per se effect of leukotrienes on the guinea-pig airways in vivo, as well as the efficacy of their receptor antagonists.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001980:Bronchi / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors; D006168:Guinea Pigs; D007213:Indomethacin / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D013189:SRS-A / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D002867:Chromones; D016861:Cyclooxygenase Inhibitors; D013189:SRS-A; C006312:FPL 55712; D011433:Propranolol; D007213:Indomethacin