Fig. 2.

ADP- and H₂O₂-mediated changes in endothelial cell impedance, Rac1 activation, and phosphorylation responses. A shows representative tracings of endothelial cells analyzed in impedance measurements in the presence or absence of ADP (50 μM), the P2Y1 receptor blocker MRS2179 (5 μM), or the H₂O₂ scavenger PEG-catalase (100 U/mL). The findings shown are representative of three identical experiments that yielded similar results. B shows representative photomicrographs of endothelial cells transfected with a plasmid encoding a Rac1 FRET biosensor and then analyzed by quantitative time-lapse microscopy before and 5 min after the addition of ADP in the presence or absence of MRS2179 (MRS) or PEG-catalase (Cat); pooled data are shown from four identical experiments, presenting the slope of the fluorescence increase following the addition of ADP, measured 5 min after adding ADP in the presence or absence of MRS2179 or PEG-catalase. C shows representative immunoblots of cultured endothelial cells incubated with ADP in the presence or absence of MRS2179, the c-Abl inhibitor bosutinib, or PEG-catalase as indicated, probed with antibodies as shown. D shows statistical analyses of pooled data from three identical experiments that yielded similar results; *P < 0.05 (ANOVA).