Vascular endothelial cells (ECs) have various functions such as the maintenance of vascular permeability, control of vascular tonus and resistance to thrombosis.
During inflammation, ECs also play a role in angiogenesis and transmigration of the leukocytes. EC injury induces inflammatory changes, vasculitis and so on. We examined the mechanism of vascular EC injury induced by the leukocytes from the standpoint of active oxygen species and adhesion molecules, CD11/CD18 and ICAM-1, EC jnjury induced by the leukocytes was due to the hydroxyl radical production from xanthine oxidase using hydrogen peroxide from the leukocytes.
In addition, CD11/CD18 and ICAM-1 induced vascular EC injury and the conversion of xanthine dehydrogenase to xanthine oxidase. The conversion might be elicited by tyrosine kinase activation.