Effect of GPIIb/IIIa inhibitor and ADP receptor inhibitor on fibrinogen binding to platelets.

Platelets pretreated with GPIIb/IIIa inhibitor (Ro44-9883, 1 μM/mL) or ADP receptor inhibitor (AR-C66096, 1 μM/mL) were activated with echicetin-IgMκ or thrombin as positive control, and binding of FITC-labeled fibrinogen was examined compared with resting platelets. All measurements were repeated 3 times with platelets from different donors. Graph shows fibrinogen binding to resting platelets (1), echicetin-IgMκ–activated platelets without inhibitors (2), echicetin-IgMκ–activated platelets with IIb/IIIa inhibitor (3), echicetin-IgMκ–activated platelets with ADP receptor inhibitor (4), thrombin-activated platelets without inhibitors (5), thrombin-activated platelets with IIb/IIIa inhibitor (6), and thrombin-activated platelets with ADP receptor inhibitor (7).