[The temperature dependence of fibrinolysis with streptokinase]

In an in-vitro study standardized test thrombi were incubated at different temperatures between 25 degrees and 43 degrees C in a constant test mixture in which all reagents necessary for fibrinolysis including streptokinase were contained in excess. At each temperature step the dilution of the standard streptokinase solution (1:1000 IU/ml) was measured at which the test thrombus dissolved in exactly 15 min (clot lysis test). The highest fibrinolysis activity (dilution of 1:1140 of the standard) was obtained at 40 degrees C, lower activities having been recorded at both higher and lower temperatures (43 degrees C:1:1000; 37 degrees C:1:900; 34 degrees C:1:550; 30 degrees C:1:255; 25 degrees C:1:90). Related to the optimal temperature of 40 degrees C (100%), the fibrinolytic activity at 25 degrees C was only 7.9%. In view of the axial temperature gradients existing in the limbs, the internal temperature in their peripheral parts lies well below the optimal temperature for fibrinolysis. This situation should be taken into account during fibrinolysis procedures for thrombotic occlusions in the limbs.