Employing a fibrin clot lysis assay, we reassessed the significance of the neutralization of
plasminogen activator inhibitor type 1 (PAI-1) activity by thrombin and factor-Xa in
fibrinolysis. When PAI-1 enriched fibrin clots were formed using increasing concentrations of
thrombin (0.1, 0.5, 1.0 IU/ml), their lysis times became shorter (43.8±4.9, 25.7±3.7, 13.9±0.8
h respectively). Times were shortened further by either heparin (43.9±11.0, 12.1±2.6,
3.6±0.2 h respectively) or vitronectin (17.0±1.6, 1.9±0.7, 0.9±0.0 h respectively). Factor-Xa …

140 Human thrombin and calcium bound factor Xa significantly shorten tPA-induced fibrin
clot lysis via a neutralization of plasminogen activator inhibitor type 1 activity: Its
enhancement by either heparin or vitronectin … 140 Human thrombin and calcium bound
factor Xa significantly shorten tPA-induced fibrin clot lysis via a neutralization of plasminogen
activator inhibitor type 1 activity: Its enhancement by either heparin or vitronectin …