Studies on the effect of PEG-modified urokinase on coagulation-fibrinolysis using beagles

Urokinase (UK), a human urinary plasminogen activator, was modified by the covalent attachment of methoxypolyethylene glycol (PEG) of 5,000 daltons. There were observed changes in substrate specificity and an increase in molecular weight in PEG-modified UK (PEG-UK). We evaluated PEG-UK by ex vivo study using beagles, and found that UK activity in the blood was well maintained over hours after intravenous injection, and that fibrinolysis was more activated compared with native UK by coagulation-fibrinolysis studies.