Effects of AR-C69931MX on platelet thrombus formation on the surface of collagen under flow conditions.

Blood containing platelets rendered fluorescent by the addition of mepacrine and anticoagulated with the specific antithrombin agent argatroban was perfused on collagen-coated glass coverslips at a wall shear rate of 1500 s^-1 for 5 minutes, either in the absence (Control) or presence of the specific P2Y₁₂ antagonist AR-C69931MX at a final concentration of 500 nM. Platelet thrombi formed on the collagen surface were detected by inverted-stage epi-fluorescent videomicroscopy (DM IRB, 1RB-FLUO, Leica, Germany), as demonstrated in the lower panel of the figure. The microscopic images were digitized online with a photosensitive CCD camera (L-600, Leica, Germany). Surface coverage by the platelets was calculated using National Institutes of Health (NIH) Image software (public domain software by Dr Wayne Rasband, NIH, Bethesda, MD, version 1.62), and the results are shown in the upper panel of the figure. These results are the mean ± SD of the 3 experiments, while the results shown in the lower panel show 1 representative result of the 3 experiments.