Platelet adhesion to apoptotic HUVEC after blockade of platelet receptors. Nonactivated platelets treated with different receptor antagonists were allowed to adhere to a HUVEC monolayer treated with staurosporine for 6 hours. Platelet binding was determined by flow cytometry as described above. The following concentrations were used: 5 μmol/L annexin V, 50 μg/mL RGE and RGD peptides, 30 μg/mL MoAb, and a dilution of 1:250 for polyclonal antibodies. Results are expressed as the mean ± SD of the median fluorescence (FL-1-H) of at least three experiments. *P < .01 by Student’st-test, compared with adhesion of nonactivated platelets treated with the isotype-specific control MoAb.