FIGURE 4.
The first layer of collagen-activated platelets support initial thrombin production. A, dynamics of measured TAT concentration and thrombin flux from growing thrombi (■) or from the first layer of collagen-adherent platelets (○) during blood (40 μg/ml CTI, 5 mm GPRP) perfusion over collagen/high TF. The αIIbβ3 inhibitor, GR144053 (500 nm) was added to abolish platelet secondary aggregation and achieve a monolayer of platelet on collagen/high TF. Initial thrombin production during the first 500 s of blood perfusion was intact, whereas the final thrombin production on collagen/high TF was significantly reduced by GR144053 (A). A platelet monolayer was sufficient to support localized fibrin formation when fibrin was allowed to polymerize in the absence of GPRP (B). **, p < 0.01.