The effect of oxidative stress on the membrane dipole potential of human red blood cells

• Published in: Biochimica et biophysica acta Vol. 1828; no. 4; pp. 1250 - 1258
• Main Authors: Jewell, S.A., Petrov, P.G., Winlove, C.P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2013
• Subjects: Benzene Derivatives - pharmacology; Di-8-ANEPPS; Erythrocyte Membrane - physiology; Erythrocytes; Humans; Hydrogen Peroxide - pharmacology; Lipid packing; Membrane dipole potential; Membrane Potentials - drug effects; Oxidative Stress; Spectrum Analysis, Raman; Oxidative stress; Lipid packing; Membrane dipole potential; Erythrocytes; Di-8-ANEPPS
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2012.12.019

The membrane dipole potential (ψd) is an important biophysical determinant of membrane function and a sensitive indicator of lipid organisation. In this study we have used the environmentally sensitive probe di-8-anepps to explore the effects of oxidative stress on the membrane dipole potential of human erythrocytes. Cells suspended in 0.15mM phosphate buffered saline containing 0.1mg/ml albumin maintained a mean value for ψd of 270 (±20) mV over the course of 1hour. In the presence of 0.4mM cumene hydroperoxide there was an increase in ψd of 14 (±7)%, accompanied by a decrease in cell diameter of ~14 (±2)%. Exposure of the cells to 0.4mM hydrogen peroxide caused ψd to decrease by 13 (±8)% at the centre of the cell and 8 (±5)% at the edge whilst the diameter remained constant. In both cases the changes were equivalent to a change in transmembrane electric field of a magnitude of ~10MVm−1, sufficient to influence membrane function. Raman microspectrometry supported the conclusion that cumene exerts its effect primarily on membrane lipids whilst hydrogen peroxide causes the formation of spectrin–haemoglobin complexes which stiffen the membrane. [Display omitted] ► The membrane dipole potential varies with curvature in normal red blood cells ► Effect of oxidative stress on membrane dipole potential is dependent on ROS present ► Hydrogen peroxide causes cell stiffening and decreased membrane dipole potential ► Cumene hydroperoxide causes cell shrinkage and increased membrane dipole potential