Stimulation with Ang1 and Ang2 induces an additive effect on neutrophil adhesion but not on P-selectin translocation. Endothelial P-selectin translocation (A) and neutrophil adhesion onto HUVECs (B) were quantified upon stimulation with either Ang1, Ang2, or both Ang1 and Ang2 (10^–10 M or 10^–9 M; 7.5 minutes). The requirement of endothelial P-selectin translocation for neutrophil adhesion (C) was demonstrated after pretreating HUVECs with rPSGL-Ig (0.01 to 1 μg/mL; 15 minutes) prior to stimulation with Ang1, Ang2, or both Ang1 and Ang2 (10^–9 M; 7.5 minutes). Data are means ± SEM of at least 7 experiments; *P = .01 compared with PBS, §P = .01 compared with corresponding agonist.