Effect of oxidized fibrinogens on blood coagulation.

We studied the effect of UV-irradiated fibrinogen on blood coagulation. Fibrinogen with oxidation degree of 10% moderately activated the intrinsic pathway, but inhibited the extrinsic pathway of blood coagulation. Fibrinogen with oxidation degree of 20% inhibited both the extrinsic and intrinsic blood coagulation pathways. We revealed disturbances in the formation of fibrin clot with oxidized fibrinogen, suppression of platelet aggregation mediated by collagen receptors, and inhibition of aggregation associated with von Willebrand factor activity. ADP initiated platelet aggregation, which was in direct proportion to the degree of fibrinogen oxidation. Our results indicate that oxidized fibrinogen produces a dysregulatory effect on platelets.