Ti{e Mode of Action of Heparins in Vitro and in Vivo

The antithrombotic action of a heparin is not necessarily confined to its effects on the clotting mechanism. Yet we restrict ourselves here to a discussion of the action of heparin on thrombin generation in platelet poor and platelet rich plasma for two reasons. In the first place it is more likely than not that inhibition of the clotting mechanism is at least one of the major working arms of heparin. All medication that inhibits blood clotting has an antithrombotic effect and all dis-orders that are known to impede clotting inhibition are accompanied by a thrombotic syndrome. Also the assumption that heparins act through their interference with blood coagulation is tacitly at the basis of vinually all studies of the pharmacokinetics and pharmacodynamics of heparin action, both clinical and experimental. Finally it is the subject that we studied and the only one that we dare to express ourselves about.