SummaryWe have demonstrated previously that fibrin enhanced plasmin formation by the vascular plasminogen activator was significantly impaired, when components isolated from the plasma of three uncontrolled diabetic patients (type I) were used to study plasminogen activation in vitro. In the present study it can be demonstrated that functional properties of the vascular plasminogen activators as well as of the plasminogens from the same three diabetic patients are significantly improved after normalization of blood sugar levels and improvement of HbAlc values. Most pronounced the Km of diabetic vascular plasminogen activator in the presence of fibrin returned to normal values, and for diabetic plasminogen the prolonged lag period until maximal plasmin formation occurred was shortened to almost control values. From these data we conclude that the observed abnormalities of in vitro fibrinolysis are not primarily associated with the diabetic disease, but might be secondary to metabolic disorders caused by diabetes.
