Erythrocyte plasma membrane potential: past and current methods for its measurement

Abstract

The plasma membrane functions both as a natural insulator and a diffusion barrier to the movement of ions. A wide variety of proteins transport and pump ions to generate concentration gradients that result in voltage differences, while ion channels allow ions to move across the membrane down those gradients. Plasma membrane potential is the difference in voltage between the inside and the outside of a biological cell, and it ranges from ~− 3 to ~− 90 mV. Most of the most significant discoveries in this field have been made in excitable cells, such as nerve and muscle cells. Nevertheless, special attention has been paid to some events controlled by changes in membrane potential in non-excitable cells. The origins of several blood disorders, for instance, are related to disturbances at the level of plasma membrane in erythrocytes, the structurally simplest red blood cells. The high simplicity of erythrocytes, in particular, made them perfect candidates for the electrophysiological studies that laid the foundations for understanding the generation, maintenance, and roles of membrane potential. This article summarizes the methodologies that have been used during the past decades to determine Δψ in red blood cells, from seminal microelectrodes, through the use of nuclear magnetic resonance or lipophilic radioactive ions to quantify intra and extracellular ions, to continuously renewed fluorescent potentiometric dyes. We have attempted to highlight the advantages and disadvantages of each methodology, as well as to provide a description of the technical aspects involved.

Cell physiology and molecular mechanism of anion transport by erythrocyte band 3/AE1

“…Quantitatively, the conductive Cl − permeability P Cl of the human red cell membrane is ∼10,000-fold lower than the permeability expected if the tracer Cl − flux were entirely conductive ( 45 ). P Cl is still larger than P Na or P K , and the red cell membrane potential is near the equilibrium potential for Cl − ( 46 – 49 ).…”

Phase angle, muscle tissue, and resistance training

“…Another bioelectrical process taking place at the cell membrane considers the cell potential model, where important ion pumps, such as the sodium-potassium pump, are coupled in the cell membrane. In human excitable cells, the intracellular medium actively conserves a polarized potential of excitation between − 3 mV to -90 mV [44], with this process depending on the selective permeability of the cell membrane to ions [45], charged molecules embedded in cell membrane structure [46] and osmotic pressure equilibrium [47]. However, when an external electrical stimulation within an optimal range of the frequencies (e.g., kHz) previously proposed [21] builds up across the cell membrane, a passive process, consisting of the electrochemical ion exchanges between the intra and extracellular mediums through ion-specific leak channels (e.g., K + leak channels), occurs below the depolarization cell membrane threshold potential [31].…”

The significance of bioelectricity on all levels of organization of an organism. Part 1: From the subcellular level to cells

“…Changes in the ionic composition of the intracellular and extracellular milieu as well as changes in the composition of molecules integrated or attached to the membrane (like the electrically negatively charged glycoproteins) lead to changes in the surface potential of RBCs (Fig. 11(f)), resulting in either depolarization or hyperpolarization (Balach et al, 2019).…”