Bronchoconstriction induced by aerosolized acetylcholine but not by acetylcholine given intravenously is inhibited by aerosolized surfactant in rats

Aerosolized pulmonary surfactant can improve respiratory function in asthmatic patients (Kurashima et al., Jpn. J. Allergol. 40, 1991). We have previously shown that pretreatment with nebulized surfactant inhibits acetylcholine-induced bronchoconstriction in rats. Underlying mechanisms of this surfactant effect are not clear. The aim of this study was to investigate whether there is a difference in bronchoconstriction induced by either aerosolized acetylcholine (ACh) or by ACh given intravenously after bronchodilator or surfactant pretreatment.