[Quantification of the effects of fibrinolytic therapy upon the flow behavior of blood (author's transl)].

The effect of Streptokinase-infusion upon the flow properties of blood was investigated by viscometric and aggregometric methods. Under fibrinolytic therapy, we found in all cases a significant fall in fibrinogen content, as well as a strong reduction in plasma viscosity, velocity of red cell aggregate formation and shear resistance of red cell aggregates. In addition, a drop in apparent blood viscosity at all shear rates was found. In no case, a total desaggregation of red cell was noted. The hematocrit value remained practically constant; consequently, the drop in apparent blood viscosity at high (160 s-1) shear rates and intermediate (8 s-1) shear rates can be solely accounted for by the observed drop in plasma viscosity. At low shear rates (2.3 s-1) the observed drop in apparent viscosity is partly caused by aggregation desaggregation, but mainly by a drop in plasma viscosity. The presented results again confirm that the method of rotational viscometry only incompletely records the improvement in the flow properties of blood that are caused by a therapy aimed at a reduction of the plasma fibrinogen content.