Peptide leukotrienes mediate acetaldehyde‐induced bronchial hyper‐responsiveness in guinea‐pigs

Abstract

We previously reported that inhaled acetaldehyde, a metabolite of ethanol and a main factor in alcohol-induced asthma, causes bronchial hyper-responsiveness (BHR) in asthmatics. However, the mechanisms are unclear. The purpose of this study was to investigate a role of a peptide leukotriene (LT) in acetaldehyde-induced BHR. Effects of LT antagonists, ONO-1078 (0.1-1.0 mg/kg) and ICI-198, 615 (0.03-0.3 mg/kg), on acetaldehyde-induced bronchoconstriction and BHR to inhaled methacholine were examined using a modified Konzett-Rössler method in guinea pigs. Acetaldehyde at 0.8 mg/ml, which failed to induce significant changes in Pao (pressure at the airway opening), enhanced an increase in Pao induced by subsequent inhalations of ascending doses (50-200 micrograms/ml) of methacholine, suggesting a potentiating effect of acetaldehyde on bronchial responsiveness. Although ONO-1078 had no inhibitory effect on bronchoconstriction caused by ascending doses (5.0-20 mg/ml) of acetaldehyde, ONO-1078 and ICI-198, 615 reduced the acetaldehyde-induced BHR. Acetaldehyde causes BHR via LT release in guinea-pigs.