Fig. 4.

ADP-dependent modulation of actin polymerization. A shows representative photomicrographs of endothelial cells that were transfected with GFP-labeled F-tractin, and then treated with PBS or ADP (50 µM), with or without MRS2179 (5 μM) or PEG-catalase. (Magnification: 100×.) (Scale bars: 5 µm.) B shows individual tracings of cellular fluorescence over time; the slope of the fluorescence increase before and 60 min after addition of ADP was determined for each experiment. The asterisk notes P < 0.05, showing a significant effect of both PEG-catalase and MRS2179 on ADP-promoted F-tractin fluorescence.