Leukocyte rolling flux and velocity in ear skin microcirculation of C57Bl/6 and PSGL-1^-/- mice. Leukocyte rolling flux (A) and leukocyte rolling velocity (B) in ear skin microcirculation of C57Bl/6 and PSGL-1^-/- mice. ▪ represent the values for leukocyte rolling flux (A) and leukocyte rolling velocity (B) in C57Bl/6 under control conditions. The remaining bars represent the experiments done in C57Bl/6 and PSGL-1^-/- mice treated 3 hours before with TNF-α intraperitoneally (0.5μg/mouse). The effects of PSGL-1 antibodies (4RA10 or 2PH1) were tested in C57Bl/6 mice. Data are presented as mean ± SEM. ^*P < .05 relative to C57Bl/6 mice treated with TNF-α.