Arginine Inhibits Hemostasis Activation

Abstract

Background: The diagnosis and the therapy of in vivo hemostasis activation is of great clinical importance. Artefactual changes of the hemostasis (i.e., coagulation or fibrinolysis) in vitro have to be prevented. Usual in vitro anticoagulation by sodium citrate does not fully inhibit coagulation—or fibrinolysis—activation. Therefore, there is need for a simple physiologic inhibitor of hemostasis activation both in diagnosis and therapy of hemostasis activation. Methods: Whole blood clotting time (WBCT), prothrombin time (PT), activated partial thromboplastin time (APTT), in vitro bleeding test closure time (IVBT-CT), and whole blood aggregometry (WBA) were determined in normal human blood or plasma, supplemented with increasing concentrations of l-arginine or guanidine. Results: Arginine in concentrations of 5–100 mM inhibited the WBCT, PT, APTT, IVBT-CT, and WBA. Arginine (50 mM) resulted in a two-fold prolongation of WBCT, PT, or IVBT-CT (the anti-epinephrine action is superior to the anti-ADP action), a four-fold prolongation of APTT or a 60% inhibition of WBA. Conclusion:l-Arginine (or guanidine) inhibited the activation of hemostasis. Arginine might be used as hemostasis stabilizer both in the diagnosis and therapy of hemostasis activation. The usage of arginine as an in vitro hemostasis inhibitor might be indicated in the diagnosis of hemostasis activation, as occuring in pharmacological thrombolysis or disseminated intravascular coagulation (DIC). The storage of blood or blood products might be improved by arginine stabilization. The amino acid (and nitric oxide precursor) l-arginine could be an interesting new pharmacologic agent to inhibit a pathologic hemostasis activation.