In vivo effects of Hb solutions on blood viscosity and rheologic behavior of RBCs: comparison with clinically used volume expanders

Abstract

HbOCs have different rheologic effects in vitro and in vivo. There are marked differences among the Hb solutions in their in vivo effects on viscosity and RBC rheologic behavior (especially at low shear rates encountered in the venous circulation and the microcirculation), which may be related to the chemical modifications applied to hemoprotein. These results could contribute to an understanding of the vasoactive effects of HbOCs.

In vitro chelating, cytotoxicity, and blood compatibility of degradable poly(ethylene glycol)-based macromolecular iron chelators

“…Therefore, the extent of RBC aggregation and hemolysis was tested in whole blood upon incubation with the P-DFO conjugates. There are several examples of macromolecules such as polyethyleneimine (PEI), fibrinogen, dextran, and polyglycerol inducing the aggregation of RBCs [60,61]. In such cases, reversible linear aggregates known as rouleaux form due to the absorption of macromolecules onto the cell surfaces between erythrocytes.…”

Hemoglobin-based oxygen carriers do not alter platelet functions: study of three chemically modified hemoglobin solutions

“…In such clinical applications the required volumes of HBOCs to perfuse are important and lead to concentrations of cell-free hemoglobin in the plasma that are 3,000-to 5,000-fold higher than the physiological plasma Hb concentration. This high concentration of cell-free hemoglobin may modify blood cells behavior [21,22] and consequently affect platelets. However, preservation of platelets functionality is essential for the clinical outcome of patients [23] in such situations.…”

The Hydrodynamic Radii of Macromolecules and Their Effect on Red Blood Cell Aggregation

“…where h and r are the viscosity and density of water at 20°C, and v v ¼ protein partial specific volume. The 12 proteins were chosen because their influence on RBC aggregation has been evaluated either directly or indirectly (Ruhenstroth-Bauer et al, 1962;Schmid-Schönbein et al, 1973;Imaizumi and Shiga, 1983;Tsai and Wong, 1996;Weng et al, 1996;Menu et al, 2000). The use of different methodologies and protein concentrations in these studies precludes a direct numerical comparison of the effects of all 12 proteins on RBC aggregation, but since at least one protein was common to two or more studies, it was possible to summarize their effects semiquantitatively (Table 3, column 5).…”