Crucial role of P-selectin for leukocyte accumulation in DVT. (A) RT-PCR of trafficking molecules in the IVC in response to flow restriction at baseline or 6 and 48 h after DVT induction (n = 5 per group). Results are shown as mean ± standard deviation. (B) RT-PCR of P-selectin in the IVC at baseline or 6 and 48 h after DVT induction (n = 5 per group). Results are shown as mean ± standard deviation. (C) Representative immunohistochemical stainings of the IVC endothelium 48 h after DVT induction showing P-selectin and vWF on the endothelial surface. Nuclei are counterstained with DAPI. Bars, 50 µm. (D, Left) Representative in vivo images of adherent leukocytes in C57BL/6 and SELP^−/− mice 6 h after induction of DVT. Leukocytes were stained with Acridine orange and visualized by intravital video microscopy (arrowhead indicates aggregates; arrows indicate single adherent cells). Bars, 100 µm. (D, Right) Quantitative analysis of firm leukocyte adhesion, 6 h after flow restriction. Firm cell adhesion is given in number per square millimeters of C57BL/6 (n = 5) and SELP^−/− (n = 7). Data are shown as mean ± SEM. (E, Left) Representative images of the excised IVC including the thrombus after 48 h in C57BL/6 and SELP^−/− mice. Bars, 1 mm. (E, Right) Thrombus weight in C57BL/6 (n = 8) and SELP^−/− mice (n = 4) 48 h after DVT induction. Dots represent individual experiments; lines show the mean of each group. (F) Histological analysis of the harvested IVC thrombi 48 h after flow reduction given as thrombus load in square millimeters (n = 5). plt, platelets. Data are shown as mean ± SEM.