The role of Akt in stable platelet adhesion to vWF under shear stress. Washed mouse platelets were preincubated with DMSO, RGDS (1 mM), SH-6 (15 and 30 μM), wortmannin (100 nM), the P2Y1 antagonist A3P5P (0.5 mM), the P2Y12 antagonist 2MeSAMP (10 μM), A3P5P and 2MeSAMP, aspirin (1 mM), or the Syk inhibitor piceatannol (10 μM) for 2 minutes, loaded onto the vWF-coated glass slides with mepacrine (10 μM), and then subjected to constant shear rate (800 s−1) for 5 minutes. After washing, adherent platelets were photographed under the fluorescent microscope as described in “Platelet adhesion under shear stress.” Numbers of adherent platelets/field were quantitated. Data (mean ± SD) were obtained from 10 randomly selected fields from each of 3 experiments. ##P < .01 vs WT platelet. **P < .01 vs DMSO-treated platelet. P < .01 for the difference between ADP receptor antagonists and SH-6 or between aspirin and SH-6. P < .05 for difference between ADP receptor antagonists and Akt knockout or between aspirin and Akt knockout.
