Thromboregulation by endothelial cells - Significance for occlusive vascular diseases

During their 7- to 9-day lifespan in the circulation, platelets perform an ill-defined baseline function that maintains the integrity of the vasculatu re. In thrombocytopenic states, there is an increase in vascular permeabili ty and fragility, which is presumably due to absence of this platelet funct ion. In sharp contrast, biochemical or physical injury in the coronary, car otid, or peripheral arteries induces platelet activation and platelet recru itment, which can progress to thrombotic vascular occlusion. Because there is 1 death every 33 seconds from vascular occlusion in the United States, t his problem has critical public health implications. In this review, we des cribe the characterization of a novel potential antithrombotic agent with a unique mode of action--biochemical "deletion" of ADP from an activated pla telet releasate, which thereby inhibits platelet recruitment and further ac tivation.