Fibrinogen Coagulation And Fibrinogen, The Mechanism Of Surface Adsorption

Fibrinogen plays an important role in clotting system and thrombosis because of its relatively high concentration compared with other blood coagulation factors in plasma. The fibrinogen is a polyelectrolyte and its configuration in solution changes in accordance with t he polyelectrolytic properties. In this investigation the fibrinogen coagulability and fibrinogen adsorption on foreign surfaces w e re studied based on the polyelectrolyte solution theoryThe study revealed that the thrombin time (TT) of fresh rabbit plasma and antithrombin III deficient plasma are shortened when the plasma are diluted with physiological solution and buffer solution and plasma dilution have the shortest TT as well as the highest plasma viscosity in shear rate 180-200 S^-1 at 25% plasma concentration. Plasma dilution increase the fibrinogen coagulability and the reduced plasma viscosity since plasma dilution weaken the inter-fibrinogen interaction and fibrinogen molecules are more expanding. The plasma viscosity, reduced plasma viscosity and fibrinogen coagulability are reduced and TT is prolongated when extra salt are added into plasma. Plasma viscosity negatively correlate with the TT and the correlation efficiency is γ =-0.55～-0.99. The reduced plasma viscosity positively correlate with the fibrinogen coagulability and the correlation efficiency is γ =0.82～-0.99. The exta salt added plasma enhance t he small ion-fibrinogen interaction and fibrinogen molecules are not more expanding in salt added plasma than normal plasma, therefore, extra salt in plasma decrease the reduced plasma viscosity a nd fibrinogen coagulability. The configuration alternation of fibrinogen in solution is in agreement with the polyelectrolytic solution theory. In physiological salt concentration the fibrinogen do not exhibit i ts strongest coagulability and can potentially increase its coagulability when the concentration of fibrinogen and small salt ions are decreased in a certain limitation. Plasma albumin in high concentration can shorten TT and increase the fibrinogen coagulability, but globulin slightly prolongate TT and decrease the fibrinogen coagulability. Protamine and polydimethyldiallyammonium chloride (S-NN) can prolongate TT and decrease fibrinogen coagulability at higher concentration, but shorten TT and increase fibrinogen coagulability at lower concentration. The polycationic substances protamine and S-NN have a critical plasma concentration, the TT is the shortest and the fibrinogen coagulability is the strongest at that critical concentration. The reduced plasma viscosity reflects the fibrinogen molecular configuration in plasma and...