Contraction of guinea-pig trachea and bronchus by honey bee venom

Isolated guinea-pig tracheal and bronchial spiral strips were relaxed by indomethacin and constricted by carbachol, histamine and honey bee venom. Constriction of the tracheobronchial smooth muscle by bee venom was not affected by indomethacin (a prostaglandin-synthetase inhibitor); methysergide (d-tryptamine receptor antagonist); compound FPL 55712 (a selective antagonist of slow-reacting-substance of anaphylasix: SRS-A) and trasylol (a potent kallikrein inhibitor). These observations appear to exclude the involvement of acetylholine, 5-HT, prostaglandins and slow-reacting substance in mediation of airway constriction by bee venom. Mepyramine (a selective histamine H₁-receptor the mediation of airway constriction by bee venom. Mepyramine (a selective histamine H₁-receptor antagonist), isoproterenol, terbutaline and salbutamol (β₂-agonists) reversed airway constriction to both histamine and bee venom. In the presence of mepyramine, bee venom relaxed guinea-pig trachea. This relaxation was inhibited by indomethacin but not by metiamide suggesting the release from the airways of inhibitory prostaglandins by bee venom. This study suggests that bee venom constricts guinea-pig airways by releasing histamine from the tissue mast cells.