Correction of impaired stable platelet adhesion to VWF in Lyn-deficient or Src inhibitor-treated platelets by exogenous cGMP. Washed mouse platelets were preincubated with DMSO or PP2 (10 μM). Wild-type (WT), Lyn^−/−, or PP2-treated platelets were then treated with 10 μM 8-bromo-cGMP and immediately allowed to adhere to VWF under constant shear rate (800 seconds) for 5 minutes. After washing, stably adherent platelets were counted under a fluorescence microscope as described for Figure 2. Shown in the figure are representative pictures and quantitative data (mean ± SD) from 3 different experiments. ##P < .01, compared with WT platelets. ***P < .001, compared with DMSO-treated WT platelets.