A crystalline nitrogenous substance recovered from inflammatory exudates induces in cutaneous tissue a rapid migration of polymorphonuclear cells through the endothelial wall of small vessels. For the sake of convenience the tentative name of leukotaxine has been proposed for this active substance which per se is capable of rapidly reproducing the basic sequences of the inflammatory reaction, namely, the initial increased capillary permeability followed by the outward migration of polymorphonuclear leukocytes. Comparison of the effect of various inflammatory irritants (e.g. turpentine or aleuronat) with that of leukotaxine indicates that the migration of cells does not seem to be primarily referable to the initial increase in vascular permeation. Furthermore leukotaxine is definitely chemotactic. It induces an active migration of leukocytes into capillary glass tubes containing this substance.
The relation of leukotaxine to the mechanism of cellular migration at the site of inflammation is pointed out.