Characteristic Changes in the Density and Shear Viscosity of Human Blood Plasma with Varying Protein Concentration

Abstract

The density and shear viscosity of human blood plasma and their dependence on the concentration of proteins (albumin, y-globulin, fibrinogen, etc.) entering the natural blood composition have been studied. The biomaterial concentration is varied by diluting the blood plasma with the isotonic aqueous solution. It is shown that a decrease in the biomaterial concentration down to 0.91 of its initial value leads to a drastic change in the plasma density and to a change in the character of the concentration dependence of the shear viscosity of blood plasma. A hypothesis is put forward that the observed changes in the density and shear viscosity result from the structural transformations induced by oligomerization processes; first of all, by the albumin dimerization. A conclusion is drawn that the introduced blood substitutes should not exceed 10% of the blood mass; otherwise, structural transformations of a biomaterial in blood plasma can be provoked.

Crucial Role of Water in the Formation of Basic Properties of Living Matter

“…The electrostatic interaction between amino acid residues with different polarities in neighbor macromolecules is not negligibly small and can invoke appreciable changes in the density and viscosity of the system. An effect of this type was observed in work [17] (see Fig. 3).…”

“…where alb = alb × 1.66 × 10 −24 g is the mass of albumin molecule, and alb is the atomic mass of albumin macromolecule (it is evaluated as alb = = 0.65 × 10 5 daltons). An important characteristic of the macromolecular solution is the the percolation threshold p = 0.23 [16,17]. At alb < p , all albumin macromolecules in the aqueous solution can be regarded as isolated; otherwise, i.e.…”

Concentration Dependences of Macromolecular Sizes in Aqueous Solutions of Albumins

“…Figure 3 demonstrates the characteristic curve = ( ) | =const that corresponds to = 42.15 ± ± 0.05Å in a concentration interval of 7.3-9.3 wt% ( = 0.22÷0.27). Note that these concentrations are somewhat higher than the percolation threshold concentration ≈ 0.23 (about 7 wt% for albumin-III), at which the protein macromolecules form infinite percolation clusters in the solution [16]. This curve has a local minimum at the temperature min = 308 ± 1 K (35 ± 1 ∘ C) and a local maximum at the temperature max = 314 ± 1 K (41 ± 1 ∘ C).…”

“…Note that the average physiological value of the acidbase balance in the sheep blood equals pH = 7.40 [13,14]. At this pH value, an albumin-III macromolecule is folded into a compact conformation like a "heart-shaped medallion" [15,16]. The experimental acid-base balance of the albumin-III solutions equals pH = 7.05, i.e.…”

“…At a concentration of 5 wt% ( ≈ 0.17), the effective radius of albumin-II macromolecules has a maximum, the position of which is almost independent of the temperature. This concentration corresponds to isolated albumin-II macromolecules because the concentration, at which they form infinite percolation clusters in the solution is equal to about 7 wt% ( ≈ ≈ 0.23) [16]. In a concentration interval of 5-20 wt% ( = 0.17÷0.49), the effective radius of albumin-II macromolecules in the solution decreases, and this behavior is almost linear at concentrations higher than 10 wt% ( > 0.32) (see Fig.…”