[The effect of heparin on eosinophil chemotaxis induced by Rantes and FMLP]

Eosinophils are important cells of inflammatory infiltration in respiratory tract of asthmatics patients. Rantes is a potent chemotactic agent for eosinophils. It belongs to the chemokine family. Heparin has been reported to diminish size of allergen skin tests and decrease response to allergen bronchoprovocation in allergic asthma. We have found that heparin diminished late phase of allergic reaction and inhibits allergen induced increase in specific and nonspecific bronchial hyperresponsiveness. In order to explore the mechanism involved in these protective effects we studied the influence of heparin on eosinophil chemotaxis induced by Rantes and FMLP. Eosinophils were isolated from peripheral blood of 12 asthmatic donors. Chemotaxis was evaluated using polycarbonate filters in 48-well chemotactic chamber. The table shows the results (*) p < 0.05. [table: see text] Ten minutes exposure of eosinophils to heparin was sufficient for inhibition. Removal to heparin by washing the cells ablated observed effects. Preincubation of Rantes or FMLP with heparin did not induce any significant changes in eosinophil chemotaxis. Heparin alone did not posess any chemotactic activity for eosinophils. Our results suggest that heparin ameliorate allergic inflammation by inhibition of eosinophil flux and this inhibition is a surface phenomenon.