Platelet and leukocyte recruitment is impaired in VWF^−/− mice. (A) IVC stenosis was produced in WT (top row) and VWF^−/− (bottom row) mice. After 6 hours, fluorescently labeled platelets or Rhodamine 6G were intravenously infused, and the cell accumulation at the area 1-2 mm below the IVC suture (toward the tail) was examined by intravital microscopy using a fluorescent microscope at ×20 magnification. Outcome: thrombus formed within 48 hours after IVC stenosis induction in a WT but not a VWF^−/− mouse. (B-C) Quantification of adherent platelets and leukocytes, respectively, 6 hours after flow restriction. (D) Kinetics of platelet accumulation 1-6 hours after flow restriction in the IVC in WT and VWF^−/− mice. Data are shown as mean ± standard error of the mean. *Statistically significant difference between WT and VWF^−/− mice. WT, n = 8-10; VWF^−/−, n = 3.