EFFECTS OF PLATELET-ACTIVATING-FACTOR ON VASCULAR-PERMEABILITY OF THEMIDDLE-EAR MUCOSA

Platelet activating factor (PAF), a potent inflammatory mediator, seem s to play a significant role in the pathogenesis of otitis media with effusion (OME), along with other inflammatory mediators such as leukot rienes and prostaglandins. The purpose of this study was to investigat e the effect of PAF on the vascular permeability of middle ear mucosa, in an experimental OME model using chinchillas. We injected PAF in do ses of 1, 4, 8, and 16 mu g and normal saline as a control into the bu llae of chinchillas. Vascular permeability was measured by the Evans b lue vital dye technique. All the PAF-injected animals showed a signifi cant increase in middle ear vascular permeability compared to the cont rol group. This study demonstrated that PAF in the middle ear cavity c ontributes significantly to the development of OME by increasing the v ascular permeability of the middle ear mucosa.