Control mechanisms in platelet activation

Those activation stages that are energy dependent rely upon a complex control mechanism involving the interaction of platelet thrombasthenin, free ionic calcium, cyclic AMP and the prostaglandins. This article describes the feedback mechanisms inherent in these controls, and the sources, activities and degradation of all control materials. Particular attention is paid to the prostaglandins and their activating enzymes, both within the dense tubular system of the platelet and the cytoplasm of endothelial cells. The implications of the prostaglandin pathway for both therapy and laboratory diagnosis are explored.