mAbp1 expression in leukocytes was required for leukocyte firm adhesion. (A) Ex vivo microflow chambers coated with recombinant murine (rm) P-selectin, rmICAM-1, and rmKC were perfused with whole blood from mAbp1^+/+ (n = 9) or mAbp1^−/− (n = 5) mice. Leukocyte adhesion was assessed after 8 minutes of perfusion. Mean number of adherent cells/FOV ± SEM (B) In vitro detachment assay of mAbp1^+/+ (○) and mAbp1^−/− () PMNs perfused through a rmP-selectin–, rmICAM-1–, and rmKC-coated flow chamber at gradually increasing shear stress levels. Initial cell number at 0.1 dyn/cm² was set to 100%. Relative adherent cells/FOV in mean ± SD; n = 7. (C) Leukocyte adhesion in TNFα-treated cremaster muscle venules of mAbp1^+/+ (□) and mAbp1^−/− () mice with medium shear rate (< 1500 s⁻¹) and high shear rate (> 1500 s⁻¹). Means of adherent leukocytes/mm² ± SEMs; n = 5; *P < .05.