Electrochemical Reactions of Blood Coagulation Factors — Their Role in Thrombosis

Abstract

AbstractThrombosis is a reaction at a solid (blood vessel wall or prosthetic material)‐electrolyte (blood) interface. It is initiated by a series of reactions of blood coagulation factors at this interface. Conducting materials, used for vascular and heart valve prostheses, which register potentials in blood more positive than +100 to +200 mv versus the normal hydrogen electrode (NHE) trigger this reaction. The same is true with positively charged insulator materials. These observations suggest an electrochemical mechanism for blood coagulation. Using electrochemical (electrocapillary, differential capacity, potentiodynamic and potentiostatic) ellipsometric, electron microscopic and hematological methods, the adsorption and charge transfer reactions, as well as where possible, their role in blood coagulation, were investigated at solid (mostly metal)‐solution interfaces. These studies reveal that: (1) adsorption of amino‐acids, peptides and proteins on metals is a potential dependent phenomenon; (2) blood coagulation factors (fibrinogen, prothrombin, thrombin, Factors V, VIII and IX) take part in electron transfer reactions; (3) fibrinogen is electropolymerised on electrodes maintained at anodic potentials; (4) fibrinogen clotting times are increased by its prior exposure to an electrode maintained at a potential of —800 mv; (5) electrochemical activation of prothrombin at positive potentials yields a product with thrombin activity; (6) heparin inhibits the adsorption of fibrinogen on freshly cleaved mica surfaces. These results are most valuable in the elucidation of the electrochemical mechanism of thrombosis. Several of the enzyme reactions in blood coagulation appear to occur by electrochemical pathways.