Comparative studies on human activators of plasminogen.

Agents activating human plasminogen have been prepared from a variety of human sources, namely plasma, blood vessel endothelium and tissue. Their physical and functional properties have been found to differ from that of the urinary activator, urokinase. Antiserum to urokinase, while it quenched the activity of urokinase itself, had no effect on the activity of the plasma, endothelial or tissue activators.