Activation of plasma fibrinolysis after intrarectal administration of high molecular weight urokinase and its derivative.

Following intrarectal administration of high molecular weight urokinase (molecular weight 53,000; 124,000 IU/mg protein) and its functionally active heavy chain (molecular weight 31,000; 212,000 IU/mg protein) to mice, activation of plasma fibrinolysis was observed. The plasma levels of pyro-Glu-Gly-Arg-pNA amidolysis and euglobulin fibrinolytic activities reached a maximum (43.4 +/- 5.3 nmol/ml and 10.8 +/- 9.4 mm2/0.03 ml, respectively) at 1-2 h after the administration of 300 IU of either enzyme per mouse, and thereafter, both activities declined slowly. Urokinase absorption into the plasma was further confirmed from the immunoreactivity of plasma enzymes isolated by affinity chromatography to each anti-urokinase serum.