ABSTRACT
Endothelial cells line the vascular wall. Because of their topological situation between blood and tissue, they are critically involved in the tissue recruitment of circulating leukocytes. The normal transit time of leukocytes through the endothelium is short, unlike that of activated leukocytes whose adhesion to endothelial cells is much stronger. Such activated leukocytes release substantial amounts of cytokines and reactive oxygen species, two families of molecules that are critically involved in the endothelial expression of cell adhesion molecules.
