[Fibrinogen seen as an independent cardiovascular factor from the molecular aspect]

The blood protein fibrinogen is one of the main independent cardiovascular risk factors and it is very likely that an increased fibrinogen level is not the consequence of cardiovascular disease but its direct cause. Fibrinogen participates actively in many processes in the organism and undergoes various changes of the molecule but it is not known what is the molecular background, why even a slight increase of the fibrinogen level is so dangerous as regards increased risk of cardiovascular attacks. In the present work the authors compared, using monoclonal antibodies, the rate of release of fibrinopeptides A and B (FpA, FpB) by the action of thrombin from fibrinogen in solution and from fibrinogen adsorbed to a solid surface. The authors revealed that the rate of FpB breakdown from sorbed fibrinogen, contrary to fibrinogen in solution is comparable to the release rate of FpA and does not depend on the release of FpA (except for competitive inhibition). The release of FpB from sorbed fibrinogen thus takes place, contrary to fibrinogen in solution, at a significant recordable rate from the very onset of thrombin action. Fibrinogen adsorption to a solid surface is associated with conformation changes which cause this effect and which lead to the formation of a two-dimensional formation formed by fibrinogen after its interaction with the surface of activated platelets.(ABSTRACT TRUNCATED AT 250 WORDS)