Time course of endothelial CD31-induced increase in the adhesive function of vβ3 integrin to RGD peptide.⁵¹Cr-labeled HUVECs were preincubated with anti-CD31 MoAb or control mouse IgG (10 μg/mL each) for 10 minutes at 37°C. After washing the cells, the binding assay of ⁵¹Cr-labeled HUVECs to RGD peptide was performed for 10 to 60 minutes at 37°C. HUVEC binding to RGD peptide is expressed as the ratio of the binding of anti-CD31 MoAb-pretreated HUVECs to that of control IgG-pretreated HUVECs. Data are the means ± SD for 3 experiments.