Effect of ABT-263 on platelet glycoprotein receptor expression and platelet activation potential in residual circulating platelets in vivo. C57BL6 mice were administered ABT-263 (25 mg/kg) or an equal volume of vehicle by oral gavage, and whole blood sampled over a 24-hour time period as described in “In vivo administration of ABT compounds.” Whole blood was analyzed for (A) P-selectin expression and (B) integrin α_IIbβ₃ activation in response to CRP (10 μg/mL) or PAR4-AP (300μM; 10 minutes). Histograms represent the data collected from 6 to 8 independent experiments (mean ± SEM). (C) Template tail bleeding time was quantified as described in “Tail bleeding studies.” Each point represents data from 1 mouse, with the mean ± SEM indicated. ns indicates not significant. *P < .05. **P < .01. ***P < .001.