Injecting sP-selectin-Fc, but not sP-selectin, promotes inflammation and coagulation in vivo. (A-B) Number of rolling cells and arrested cells in trauma-stimulated venules of WT mice injected IV with saline, sP-selectin, sP-selectin-Fc, or control-Fc in the presence or absence of blocking anti-P-selectin mAb or anti-β2 integrin mAb. (C) Percentage of tissue factor–positive microparticles in plasma of WT mice 22 hours after intraperitoneal injection of saline, sP-selectin, sP-selectin-Fc, or control-Fc. (D) Plasma-clotting times of WT mice 22 hours after intraperitoneal injection of saline, sP-selectin, sP-selectin-Fc, or control-Fc, in the presence or absence of blocking anti-tissue factor IgG or nonimmune IgG. (E) Plasma levels of sP-selectin or sP-selectin-Fc 22 hours after intraperitoneal injection. The data in panels A and B represent the mean ± SEM from 15 to 20 venules from 4 to 5 mice in each group. The data in panels C-E represent the mean ± SEM from 7 to 12 experiments in each group. *P < .05, **P < .01, ***P < .001.