A NEW PHARYNGITIS MODEL USING CAPSAICIN IN RATS

1. Application of capsaicin solution onto the rat pharyngeal mucosa ca used a well-reproducible increase in vascular permeability in the phar ynx. 2. Capsaicin induced pharyngeal inflammation was unaffected by a histamine H-1 blocker and non-steroidal anti-inflammatory agents, wher eas dexamethasone was effective in its inhibition. 3. FK224, a dual an tagonist of tachykinin NK1 and NK2 receptors, and FK888, a selective a ntagonist of NK1 receptor, significantly inhibited capsaicin induced p lasma exudation in the pharynx. 4. In capsaicinized animals, the appli cation of capsaicin solution in the pharyngeal mucosa did not induce p haryngitis. 5. These results suggest that the mechanism of the capsaic in-induced pharyngitis primarily involves tachykinins. (C) 1998 Elsevi er Science Inc.