Human endothelial cells activated with IL-1 express a surface membrane-oriented procoagulant generating system characterized by increased tissue factor synthesis and decreased thrombomodulin activity. We now report that IL-1 also stimulates endothelial cell synthesis of plasminogen activator inhibitor. This array of IL-1-induced activities shifts the balance at the endothelial cell surface to a prothrombotic influence and may reflect an early response of the blood vessel wall to injury.
