Figure 7

Effect of RTL on platelet function and occlusive thrombus formation. The effect of RTL1000 on A) aPTT or B) the clotting time of PPP in the presence of excess molar Ca²⁺. In selected experiments, plasma was pretreated with vehicle, RTL1000 (10 μg/ml), the anti-FXI mAb 14E11 (20 μg/ml) or tissue factor (TF, 1 pM). C) Washed human platelets (2 × 10⁸/ml) were pretreated with either vehicle or RTL1000 (10 μg/ml) for 2 min prior to stimulation with collagen (2 μg/ml). The extent of platelet aggregation was observed using a Chrono-Log aggregometer. D) Whole human blood in 0.38% sodium citrate was recalcified and perfused through a collagen-coated glass capillary until occlusion. Blood flow was driven by a constant pressure difference. In selected experiments, blood was pre-treated with either 10 or 50 μg/ml RTL1000. Data are reported as mean ± SEM of at least 3 experiments. * P < 0.05 compared to vehicle.