Role of platelets in soluble tissue factor-induced footpad inflammation. Immune thrombocytopenia was induced in protease activated receptor PAR-4+/+ mice by a single antiplatelet antibody treatment given 16 hours prior to soluble tissue factor injection. (a) Platelet counts were performed 40 hours after injection of antibody. (b) Footpad swelling was greatly reduced in mice treated with antiplatelet antibody. Antiplatelet antibody-treated mice, n = 10; control, rabbit normal serum-treated mice, n = 10. *P < 0.05, **P < 0.01, t test.