EFFECT OF A LEUKOTIENE ANTAGONIST,ONO-1078,ON ELEC-TRIC STIMULATION OF VAGUS(ESV)-INDUCED DRONCHO CONSTRICTION AND MICROVASCULAR LEAKAGE IN GUINEAPIGSEQ

In atropine-pretreated guinea pigs, electric stimulation of vagus(ESV,10 Hz,5ms,2V or 10V,for 90s)increased intrapulmonary pressure(IPP),and Evans blue extravasationin trachea,main bronchi,peripheral and distal intrapulmonary airways in a voltage-dependentmanner.ONO-1078,a noval leukotriene antagonist,(0.03 and0.1mg·kg^-1,iv)showed noremarkable inhibiting effect on ESV-induced increase of IPP.However,the agent significantlyinhihited ESV-induced increase of Evans blue extravasation in the airways,especially in lower potencyof stimulation(2V).The results suggest that leukotrienes may be involved in airway microvascularleakage in response to neurogenic inflammation.