[Inhibitory effect of ONO-1078, a novel leukotriene receptor antagonist, on human peripheral blood eosinophils].

To determine whether ONO-1078, leukotriene receptor antagonist, inhibits the activation of eosinophils, we investigated the effect of ONO-1078 on the release of leukotriene (LTC4) and eosinophil cationic protein (ECP) from human peripheral blood eosinophils of allergic patients and normal subjects. After preincubation with ONO-1078, eosinophils were incubated with calcium ionophore (A23187). ONO-1078 10(-5) and 10(-6) M inhibited LTC4 release of allergic patients eosinophils and 10(-5)-10(-9) M inhibited LTC4 release of normal subjects eosinophils. ONO-1078, 10(-5) M, also inhibited ECP release of eosinophils obtained from both asthma patients and normal subjects. We think that ONO-1078 may have another pharmacological effect to prevent the activation of human peripheral blood eosinophils by inhibiting LTC4 and ECP release. These results suggest that ONO-1078 might be useful in controlling bronchial asthma.