Quantification of ICAM-1 adhesion.

(A) αICAM-1-antibody coated-beads were allowed to pre-adhere to TNF-α-stimulated endothelium for 5 minutes. Experiment was carried out as described in Materials and Methods. Briefly, low shear was introduced (0.25dyn/cm²) and flow was increased stepwise with 1.25dyn/cm² at the time points, indicated with arrows. The final shear corresponded to 6.25dyn/cm². The αICAM-1-antibody coated beads detached from the endothelium when shear increased. Pre-treatment of the endothelium with cytochalasin B (CytoB) or NSC-23766 (NSC) showed a steeper decline of detached beads upon increased shear flow. Experiment is done three times. Data are mean ± SEM. *p<0.05. (B) Experiment carried out as described under A. Pre-treatment of the endothelial cells with either blebbistatin (Blebbi) or cyclodextrin (β-CD) show a decrease in adhesion of the beads to the endothelium, already after the first increase in shear flow. Experiment is done three times in duplicate. Data are mean ± SEM. *p<0.01.