In vitro effect of dextran-benzene-tetra-carboxylate hemoglobin on human blood rheological properties.

While conducting pharmacological investigations into oxygen carriers, it is important to study the in vitro and in vivo rheological behavior of blood cells in the presence of such preparations. With regard to the original nature of human hemoglobin bound to benzene tetracarboxylate substituted dextran (Dex-BTC-Hb), it seemed necessary to study its rheological effect in a simulated in vitro hemorrhagic shock compensated by a blood substitute. The viscosity of substitutes was determined as well as several rheological parameters after 0, 3 and 6 hours incubation periods of red blood cells with substitutes: viscosity of blood-substitute mixtures at different levels of plasma substitution erythrocyte aggregation of blood-substitute mixtures by determining the velocity of rouleau formation and the cohesion of rouleau network. This work yielded several observations: The viscosity of Dex-BTC-Hb was slightly higher than those of solutions of native Hb, Dex-BTC T10, Dextran 40 (Plasmacair, modified fluid gelatin (Plasmion and hydroxyethyl starch 200 (Elohes). The substitution of a blood volume with Dex-BTC-Hb, corresponding to a compensated 45% hemorrhagic shock, slightly increased the viscosity of hemodiluted blood as compared to other substitutes. In the presence of Dex-BTC-Hb, the aggregation of erythrocytes appears to be increased as compared to standard solutions. Yet, the effect was close to that of Plasmion or Elohes.