Effect of Oxidized Fibrinogen on Aggregation of Activated Platelets and Neutrophils

The effect of oxidized fibrinogen on platelet-neutrophil complex formation was evaluated by studying the platelet aggregation (changes in light transmission and turbidimetric assay). Activation of cells by thrombin (0.015 U/ml) in the presence of oxidized fibrinogen was accompanied by the formation of larger intermolecular aggregates of platelets and leukocytes as compared to those detected in experiments with non-oxidized fibrinogen. Addition of thrombin (0.2 U/ml) in the presence of oxidized fibrinogen was followed by the formation of more stable complexes of platelets and leukocytes as compared to those revealed in experiments with non-oxidized fibrinogen. An increase in the width of aggregation curves was most pronounced in the system of 10 −4 M Fe 2+ and 10 −4 M H 2 O 2 with oxidized fibrinogen. Our results indicate that oxidized fibrinogen contributes to the “floating” or suspension of platelet-leukocyte complexes.