Fig. 1.

Inhibitory properties of endothelial cells. Inhibition of platelet function and coagulation by several endothelial molecules and factors and the targeted coagulation factors are shown. Endothelial cells (ECs) express nitric oxide (NO), prostacyclin (PGI₂), and ectonucleoside triphosphate diphosphohydrolase-1 (E-NTPDase1), which inhibit platelet adhesion and aggregation. Heparin-like molekules (Hep) expressed on endothelial surface serve as a cofactor for antithrombin III (ATIII) inactivating several coagulation factors. ECs express tissue factor pathway inhibitor (TFPI), which limits the action of tissue factor (TF) and inhibits excessive TF-mediated activation of coagulation factors VII and X. Thrombomodulin (TM) binds thrombin activating protein C and degrades factor Va and VIIIa. Activation of fibrinolysis by endothelial tissue plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) and their inhibition by plasminogen activator inhibitor (PAI-1) is depicted. PLG plasminogen