Influence of plasma proteins on the in vivo and in vitro rheological properties of blood

Plasma proteins have a multiform effect on blood rheology and circulation. I. Plasma viscosity increases as the concentration or molecular weight of protein increases. When high molecular weight proteins are present, non-Newtonian rheology is evident. II. Rigidity/fluidity of the red cell is influenced by the ratio of the internal viscosity of the red cell to the viscosity of plasma; and may be affected by adsorption of proteins onto the red cell membrane. III. Aggregation of red cells greatly increases in the presence of paraproteins, and the morphology of aggregates may be affected by protein composition. IV. Viscosity of whole blood is affected by proteins via the blood subphases; actual determination of blood viscosity can be affected by flow instability which is also related to the proteins present. V. Thrombus formation is affected by plasma proteins through interference with platelet aggregation and polymerization of fibrinogen. VI. Coating of blood vessels by proteins (especially fibrinogen/fibrin) might influence flow rate. VII. Control of hyperviscosity can be carried out by plasmapheresis, etc.