Activated platelets synthesize TIMP-2 protein. (A) Intracellular or released TIMP-2 protein in unactivated or thrombin-activated (0.1 U/mL, 60 minutes) platelets. The bars represent the mean ± SEM of 8 independent experiments. (B) TIMP-2 protein that is secreted into the supernatants of thrombin-activated platelets over 16 hours. The bars represent the mean ± SEM of 8 independent experiments. (C) Incorporation of [³⁵S]methionine/cysteine into TIMP-2 protein (intracellular and secreted) in thrombin-activated platelets. The bars, which display the mean ± SEM of 5 independent experiments, represent the fold increase over baseline of [³⁵S]methionine/cysteine that incorporates into TIMP-2 protein.