Initial Studies on the Effect of Inhaled Misoprostol in a Guinea Pig Model of Allergic Bronchoconstriction

Inhaled E series prostaglandins (PGEs) have been shown to modulate responses to both allergic and nonallergic provocation. Little is known about the effect of inhaled misoprostol on the airway and whether its antiasthmatic activity would be similar to other PGEs. In the present study, nebulized solutions of misoprostol and PGE(2) (0.3--300 &mgr;g ml(minus sign1)) effectively blocked the acute bronchospasm due to inhaled antigen challenge in actively sensitized guinea pigs. A 300-&mgr;g ml(minus sign1) solution nebulized for 10 s (about 0.25 ml), 5 min prior to challenge, provided nearly complete inhibition with significant reductions seen at 30 and 3 &mgr;g ml(minus sign1) in certain experiments. Misoprostol treatment resulted in a significant reduction in the number of eosinophils present in bronchoalveolar lavage 24 h after antigen challenge. This combination of effects suggests that inhaled misoprostol may be effective in the treatment of the acute and chronic symptoms of asthma.