FIGURE 4.

Contribution of PI3Kα and -β isoforms to GPVI-induced α-granule secretion. Human washed aspirin-treated platelets (1 × 10⁸/ml) were preincubated with ADP receptor blockers (Fig. 2) and treated with Me₂SO vehicle (control) or specific PI3K inhibitor (in micromolar): PIK-75 (1.0), TGX-221 (0.5), wortmannin (0.1), and LY-294002 (25). The platelets were activated for 10 min with convulxin (70 ng/ml) or CRP (10 μg/ml). A, histogram showing effect of PI3Kα/β blockers on P-selectin expression (FL1 fluorescence). B, quantitative effect of PI3K blockage on P-selectin expression. Data are relative to the control condition. Means ± S.E. (n = 3); *, p < 0.05 compared with control.