Human red blood cell aging: correlative changes in surface charge and cell properties.
Bottom Line: Therefore, to remove the ambiguity and uncertainty, we carried out multiparameteric studies on Percoll fractions of blood of 38 volunteers (lightest-young-Y-RBCs, densest-old-O-RBCs, two middle fractions).We found that there were striking differences between the properties of Y-RBCs and O-RBCs.The ζ-potential of Y-RBCs decreased gradually with aging.Close correlation was found between the surface charge on an aging RBC and its structure and functions, from the cell morphology, the membrane deformability to the intracellular Hb structure and oxidation ability.
Affiliation: Institute of Biomedical Engineering, Ji Nan University, Guang Zhou, China. email@example.comShow MeSH
Related in: MedlinePlus
Mentions: Figure 2A shows the adult human RBCs fractionated by Percoll: the lightest top fraction- young RBCs (denoted as Y), two middle fractions (M1 and M2) and the bottom, the densest fraction-old-RBCs (denoted as O). We can see that the four fractions were separated quite clearly. Figure 2B–E shows the fluorescence images from QD bound to Y-RBCs, M1, M2 and O-RBCs, which were fractionated by Percoll. We proved previously that by using the collinear relation between the fluorescent intensity and ζ-potential (or charge density), the fluorescent intensity at each pixel of the image can be used to estimate the magnitude of the surface charge density at the point . Therefore, in Figure 2F the relation between the fluorescent intensities and the ζ-potentials for Y-RBCs, M1, M2 and O-RBCs is shown to indicate that there is really a collinear relationship between the two parameters. Figure 2G presents the enlarged images of QD-labelled Y-RBC to clearly show that there is a very bright intense orange fluorescence ring around the cells and on the cell surface with the dark centre arising from the biconcave discoid doughnut shape of RBCs. Table 1 lists the detailed information about the numbers of cells and the averaged values of ζ-potential in each fraction harvested by the Percoll density centrifugation in 2 ml of peripheral blood from the well-defined layers. All these results show a gradual decrease of ζ-potentials of RBCs in the various fractions, i.e. from those in the lightest fraction of Y-RBCs through to those in the middle fractions, M1, M2 down to the densest O-RBCs, revealing a collinear relationship between the decreasing ζ-potentials and the intensity of fluorescence from QDs bound to all the electron charges on the cell fractions. These differences between ζ-potentials were independent of gender.
Affiliation: Institute of Biomedical Engineering, Ji Nan University, Guang Zhou, China. firstname.lastname@example.org