Effect of inhibitors of leukotriene and/or platelet activating factor on killed H. influenzae induced experimental otitis media with effusion.

Our previous studies have shown that leukotriene (LT) and platelet activating factor (PAF) are important inflammatory mediators (IMs) in the pathogenesis of otitis media with effusion (OME). The purpose of this study was to determine the effect of a LT-inhibitor and/or PAF-antagonist on experimentally induced OME by killed H. influenzae in chinchillas. LT-inhibitor SCH-37224 and/or PAF-antagonist WEB-2170 were systematically administered, each separately or in combination, 2h prior and then at regular intervals after the injection of killed H. influenzae into the superior bullae. After 48h, OME was completely prevented in the combination group while it was only partially prevented in the other two separately treated groups. Animals in the control group all developed OME. Findings of this study suggest the importance of LT and PAF in the pathogenesis of OME and the usefulness of their blockers in the prevention of OME suggesting possible future therapeutic implication.