HUVEC adhesion to different matrix glycoproteins. HUVEC adhesion to fibronectin (▦), vitronectin (□), and collagen IV (50 μg/mL diluted in PBS; ▪) was measured. Cells were seeded in the presence of 10% FCS and treated for one hour at 37°C with serial dilutions of RGDS or RGES. Cell adhesion was then quantified as optical density (OD) at 595 nm and expressed as OD percent versus control. (A) RGDS reduced in a dose-dependent manner HUVEC adhesion to fibronectin and vitronectin, but it did not inhibit adhesion to collagen IV (^*P < .001). (B) Control peptide RGES had no effect on HUVEC adhesion to extracellular matrix glycoproteins. Data are expressed as mean ± SE of 3 experiments carried out in triplicate.