P2Y12 in Atherothrombosis Figure 8. Deficiency of murine P2Y12 receptors affects thrombus formation on plaque at high shear rate. Citrate-anticoagulated blood from P2Y122/2 and corresponding wild type (P2Y12+/+) mice was supplemented with OG488-fibrinogen (25 mg/ml) and co-perfused with ADP (10 mM) over homogenized murine plaque material at 1000 s21 for 4 min. (A) Representative phase-contrast and fluorescence images (bar = 20 mm). (B) Average size of thrombi after perfusion. (C) Average fluorescence intensity (arbitrary units) from fibrin(ogen)-binding platelets and thrombi. (D) Histograms of features on surface; estimated numbers of platelets per feature were 9–24 (white), 24–75 (light gray), 75–400 (dark gray) and .400 (black). (E) Disaggregation events measured per platelet aggregate per min. Data are means 6 SE (n = 3), *p,0.05. doi:10.1371/journal.pone.0010130.g008 Author Contributions Conceived and designed the experiments: JWMH MJEK. 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