Platelets differentially express and release MMP and TIMP proteins. MMP and TIMP protein expression was analyzed as described in “Protein expression.” (A) Intracellular or released protein for MMPs 1 and 2 in unactivated or thrombin-activated (0.1 U/mL, 60 minutes) platelets. The bars represent the mean ± SEM of 5 or more independent experiments. (B) Intracellular or released TIMP-1 and TIMP-3 protein in unactivated or thrombin-activated (0.1 U/mL, 60 minutes) platelets. The bars represent the mean ± SEM of 5 or more independent experiments.