Platelets increase carotid ligation–induced VSMC inflammation in mice. (A) Platelets are activated after carotid ligation. The left carotid artery was permanently ligated, and the mice were treated with platelet-depleting antibody or control IgG. Plasma PF4 was measured by ELISA (n = 5 ±SD; *P < .01 vs 0). (B) Platelets promote inflammation in carotid ligation model. Plasma IL-6 was measured by ELISA in control and platelet-depleted mice after carotid ligation (n = 5 ± standard deviation [SD]; *P < .01 vs 0).