Inhibition of Plasminogen Activation and Plasmin Activity after Euglobulin Precipitation and Acidification of Plasma

Plasmin inhibitor was measured in plasma, acidified plasma, euglobulin fraction, and supernatant after euglobulin precipitation. On average, acidified plasma contained 20%, and euglobulin 9%, of the original plasmin inhibiting activity. From experiments with urokinase activation of euglobulin it was suggested that euglobulin contained acid-and heat-labile inhibiting activity against plasminogen activation by urokinase. No loss of plasminogen occurred during acidification of the euglobulin.