Abstract
We investigated the effect of WEB 2086, a selective platelet-activating factor (PAF) receptor antagonist, on PAF-induced eosinophil chemotaxis and LTC4 production. WEB 2086 inhibited PAF-induced eosinophil chemotaxis in normals and asthmatics. To further determine if WEB 2086 is a selective PAF receptor antagonist, we examined the effect of WEB 2086 against formyl-methionyl-leucyl-phenylalanine (fMLP)-induced or eosinophil chemotactic factor of anaphylaxis (ECF-A)-induced eosinophil chemotaxis. WEB 2086 did not have a significant inhibition against fMLP or ECF-A-induced eosinophil chemotaxis. These results suggest that WEB 2086 is a selective and potent inhibitor of PAF-induced eosinophil chemotaxis and LTC4 production from eosinophils, due to its antagonism of PAF-receptors.