Inhibitory effect of heparin on leucocyte chemotactic factors.

Heparin inhibits attraction of leucocytes to chemotactic factors in human skin windows in a dose-dependent fashion. These findings can be reproduced by in vitro chemotaxis studies with zymosan-activated serum, bacterial factor or eosinophil chemotactic factor as chemoattractants. Evidence is presented that the mechanism of this inhibition is an interaction of heparin with the chemotactic factors themselves and not with the migrating leucocytes. Two other mucopolysaccharides, chondroitin sulphate A and hyaluronic acid, are also potent inhibitors of chemotactic factors. These findings suggest a physiological mechanism whereby inflammatory processes can be modulated at tissue sites and within the peripheral circulation.