Oxidation of human red blood cells by a free radical initiator: effects on rheological properties.

The main aim of this study was the investigation of the rheological properties of Red Blood Cells (RBCs) obtained from subjects admitted to blood donors, associated with the lipid profile of High-Density Lipoprotein Cholesterol (HDL-C), Low-Density Lipoprotein Cholesterol (LDL-C), Triglyceride (TG) and Total Cholesterol (TOT-C). The deformability index of RBCs was determined by using a Dynamic Stress Rheometer (DSR-500) under oxidative injury induced by 2.2'-azo-bis (2-amidinopropane) dihydrochloride (AAPH). An increased rigidity of RBCs in subjects with borderline level of hyperlipidemia was found, compared with the control group. In order to explain the reason for the reduced deformability, a borderline group was studied for the evaluation of anionic permeability on membrane, haemolysis and morphological changes induced by AAPH, as well as ThioBarbituric Acid Reactive Substances (TBARs) generation. Haemolysis by AAPH indicated a decrease of globular resistance in the borderline group, furthermore, the elevated values of TBARs suggested lipid peroxidative damage to the RBCs membrane associated with morphological changes and anion permeability alterations. Our study shows the correlation between biochemical and morphological parameters of RBCs and their rheological behavior during oxidative injury. Rheological studies might be useful as a clinical and diagnostic monitoring technique and provide support for further research.