With the use of photoelectric scanning optics on the analytical ultracentrifuge molecular weights on human plasminogen and plasmin have been determined at levels as low as 50 pg per ml and as low as 10 pg per ml for the sedimentation coefficient. The results give a molecular weight of 81,000 for human plasminogen and 75,400 for human plasmin. The molecular weight difference has been verified wi...

The antifibrinolytic activity was found in the medium of platelet suspension in the process of platelet aggregation induced by thrombin, ADP and 5-hydroxytryptamine. The antifibrinolytic activity was closely associated with inhibitors in platelets, which specifically inhibited plasmin activity and not inhibited other proteases such as urokinase, thrombin and trypsin. One casein unit of plasmin ...

Fibrinolytic activity and plasmin inhibitor activity were determined by Blue Dextran-fibrin method in patients with acute myocardial infarction. The normal values of fibrinolytic activity and plasmin inhibitor activity were 3.34 +/- 0.74 units and 10.10 +/- 2.39 units (mean +/- SD), respectively. The fibrinolytic activity in normal women (3.63 +/- 0.99 units) was slightly higher than that in no...

The success of plasminogen activators in recanalizing occluded coronary arteries may be influenced by their effect on blood platelets; however, some previous studies have shown platelet activation by plasmin and thrombolytic agents while others have shown an inhibitory effect. Moreover, it has not been determined whether these effects reflect an alteration of intracellular signal transduction, ...

Vascular endothelial cells (EC) play an active role in the synthesis and assembly of components of the fibrinolytic system and the generation of the major fibrinolytic protease plasmin. However, the reciprocal effects of plasmin on EC function have not been previously examined. We have studied the actions of plasmin on the production of prostacyclin (PGI2) by cultured human umbilical vein (HUVE...

Excess excitatory amino acids can provoke neuronal death in the hippocampus, and the extracellular proteases tissue plasminogen activator (tPA) and plasmin (ogen) have been implicated in this death. To investigate substrates for plasmin that might influence neuronal degeneration, extracellular matrix (ECM) protein expression was examined. Laminin is expressed in the hippocampus and disappears a...

Coagulation factor XIIIa (FXIIIa) is a transglutaminase that covalently cross-links fibrin and other proteins to fibrin to stabilize blood clots and reduce blood loss. A clear mechanism to describe the physiological inactivation of FXIIIa has been elusive. Here, we show that plasmin can cleave FXIIIa in purified systems and in blood. Whereas zymogen FXIII was not readily cleaved by plasmin, FXI...