Inhibition of angiogenesis by thromboxane-stimulated platelet releasates. (A) Endothelial cell migration after exposure to the releasate from resting platelets (plts; control) or platelets activated with 100μM TXA₂. (B) Capillary tube formation with exposure to the releasate from platelets activated with 100μM TXA₂. The scale bar is 300μm in size. (C) Quantification of branch points generated by the releasate of platelets alone or platelets exposed to TXA₂. * indicates P < .05.