Eicosanoids in the local regulation of haemostasis

Prostaglandin 12, a potent antiplatelet agent, is formed by arterial wall cells to a differing extent. Various mechanisms are involved regulating synthesis and degradation. The mechanisms by which PGI2 exerts its biological action are still under debate. The most prominent ones are the action on fibrinolysis, thromboresistance, smooth muscle cell proliferation, extracellular matrix formation, endothelial stability, lipid metabolism, cytoprotection, and white blood cells among others. In vivo investigations have proven some of these mechanisms in human. The decreased thrombogenicity, endothelial stabilization, and reduction in intravascular lipids can be visualized under gamma-camera after autologous labelling of platelets or LDL, respectively. The local interaction of eicosanoids with other compounds regulates hemostasis in a rather complex system.