Urokinase-type plasminogen activator (uPA) is synthesized as single-chain protein (scuPA) with little intrinsic activity. scuPA is activated when it is converted to two-chain urokinase (tcuPA) by plasmin or when it binds as a single-chain molecule to its cellular receptor (uPAR). Previous data indicate that complexes between scuPA and its receptor have somewhat higher affinity for plasminogen t...

Activation of plasminogen by urokinase plasminogen activator (uPA) plays important roles in several physiologic and pathologic conditions. Cells secrete uPA as a single-chain molecule (scuPA). scuPA can be activated by proteolytic cleavage to a 2-chain enzyme (tcuPA). scuPA is also activated when it binds to its receptor (uPAR). The mechanism by which the enzymatic activity of the scuPA/suPAR c...

Tissue and urokinase-type plasminogen activators are serine proteases with highly restricted specificity, their best characterised role being to release the broad specificity protease plasmin from inactive plasminogen. It has frequently been suggested that these, and similar proteases, are involved in axonal growth and tissue remodelling associated with neural development. To help define what t...

The local environment of neurosecretory cells contains the major components of the plasminogen activation system, including the plasminogen activators, tissue plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), as well as binding sites for t-PA, the receptor for u-PA (uPAR), and also the plasminogen activator inhibitor, PAI-1. Furthermore, these cells express specific ...

The principles relating the lysis times of fibrin clots to their contents of fibrin, plasminogen and plasminogen-activator were investigated. Mathematical considerations suggested that the square of the lysis time should correlate linearly with the fibrin content, and inversely with the activator and the plasminogen contents of the system. Experimental studies, during which these parameters wer...

T hrombosis of a coronary or cerebral artery is the most common cause of mortality and morbidity in the developed nations.' The proximate cause is most often atherosclerosis, and the most appropriate intervention is its prevention. Much progress has been made in identifying the risk factors predisposing to atherosclerosis, and, perhaps because of their recognition, a significant decrease in the...

T hrombosis of a coronary or cerebral artery is the most common cause of mortality and morbidity in the developed nations.' The proximate cause is most often atherosclerosis, and the most appropriate intervention is its prevention. Much progress has been made in identifying the risk factors predisposing to atherosclerosis, and, perhaps because of their recognition, a significant decrease in the...

T hrombosis of a coronary or cerebral artery is the most common cause of mortality and morbidity in the developed nations.' The proximate cause is most often atherosclerosis, and the most appropriate intervention is its prevention. Much progress has been made in identifying the risk factors predisposing to atherosclerosis, and, perhaps because of their recognition, a significant decrease in the...

The fibrinolytic pathway maintains vascular patency by the proteolytic degradation of fibrin, the end-product of coagulation. Formation of a fibrin mesh during haemostasis is part of the physiological response to vascular injury, whereas thrombosis is a pathological obstruction of blood flow, but the biochemical and cellular participants are believed to be similar. Physiological fibrinolysis is...