Figure 3.

SR12813 inhibits platelet aggregation, integrin αIIbβ3 activation and secretion. Human washed platelets (4 × 10⁸ cells/ml) pre-treated with SR12813 or vehicle-control (DMSO, 0.1% v/v) were stimulated with (A,B) collagen (EC₅₀: 0.5–0.8 µg/ml) or (C) thrombin (EC₅₀: 0.03–0.04 U/ml). Representative aggregation traces are shown. Quantified data displays the percentage of aggregation (vehicle-treated samples represent 100% aggregation) at the end of 5 minutes. (D) Human PRP treated with SR12813 or vehicle for 10 minutes was stimulated with CRP-XL (EC₅₀: 0.25 µg/ml) or thrombin (EC₅₀: 0.05 U/ml) and fibrinogen binding to integrin αIIbβ3 was measured using flow cytometry. (E) P-selectin exposure was measured in SR12813 treated PRP, stimulated with CRP-XL (0.25 µg/ml) or thrombin (0.05 U/ml). Vehicle-treated control is defined as 100% fibrinogen binding and P-selectin exposure. ATP release was monitored for 5 minutes in washed platelets (4 × 10⁸ cells/ml), incubated with SR12813 or vehicle-control for 20 mins and stimulated with (F) collagen (1 µg/ml) or (G) thrombin (0.05 U/ml). Representative traces and quantified data are shown. Vehicle-treated samples represent 100% ATP secretion. (H) TxB₂ production was evaluated in human washed platelets (4 × 10⁸ cells/ml) pre-incubated with SR12813 or vehicle control for 20 min and stimulated by CRP-XL (1 μg/ml) or thrombin (0.05 U/ml) for 5 minutes. Data represent mean ± SD (n ≥ 3), *P < 0.05, **P < 0.01 and ***P < 0.001 was calculated by one-way ANOVA. Figure adapted from corresponding PhD thesis⁴⁸.