Platelets are required for the VWF effect on PMN recruitment. Mice were treated with an isotype control (black bars) or with a platelet-depleting antibody (white bars). After 24 hours, control rabbit IgG (Co-IgG), anti-P- and L-selectin antibodies, or rabbit anti-VWF antibodies were injected, and peritonitis was induced 15 minutes later with thioglycollate. Transmigrated PMNs were counted after 2 hours. For determination of statistical significance, data were compared with nondepleted Co-IgG-treated mice. Error bars show SEM (groups of 4 or more). Comparable results were achieved in 2 independent experiments. ***P ≤ .001; *P ≤ .05.