Conductometric properties of human erythrocyte membranes: dependence on haematocrit and alkali metal ions of the suspending medium

Abstract

The electrical properties of the cytoplasmatic membrane of human erythrocyte cells have been evaluated by means of dielectric spectroscopy measurements in the radiowave frequency range, using the so-called "suspension method". Measurements have been carried out at different volume fractions of the corpuscular phase (the cell haematocrit) in order to investigate the influence of the cell-cell interactions on the electrical parameters (the membrane permittivity epsilon and the membrane conductivity sigma) of the cell membrane and a set of new values are proposed. Moreover, the influence of different alkali metal ions (Na+, K+, Cs+, Li+) on the ion permeation properties of the membrane are investigated and the structural alterations in the membrane organized briefly discussed.

Structural alteration of erythrocyte cell membrane in presence of artificial prostheses: A radiowave dielectric spectroscopy study

“…21 It must be noted, however, that in the present case, the dielectric analysis is based on different suspension model equations (the MaxwellWagner-Hanai and Looyenga equations) that are developed to take into account relatively high values of the fractional volume ⌽. In particular, the Looyenga equation has been derived for highly concentrated suspensions, and hence it should work in a "correct" way for samples investigated here.…”

On the dielectric relaxation of biological cell suspensions: The effect of the membrane electrical conductivity

“…While Bao et al [21] limited themselves to determine the specific cytoplasm conductivity ( p = 0.518 ± 0.007 mho/m), Bordi et al [22,23] for erythrocyte cells in NaCl solution at an haematocrit of˚= 0.30 found a value of the membrane conductance of G = 3.17 × 10 −3 mho/m 2 and for erythrocytes dispersed in different alkali metal ion solutions, they found membrane conductivity s ranging from 10 −4 to 10 −3 mho/m. In particular, the membrane conductivity, extrapolated to =0 assumes values of s = (5.09 ± 0.08) mho/m in the presence of Na + ions, a value of s = (1.45 ± 0.04) mho/m in the presence of Li + ions, a value of s = (1.46 ± 0.05) mho/m in the presence of Cs + and, finally, a value of s = (0.91 ± 0.03) mho/m in the presence of K + ions ions.…”

Effect of the shape of human erythrocytes on the evaluation of the passive electrical properties of the cell membrane

“…This technique has been applied to different types of biological systems, ranging from human normal and pathological erythrocytes [5][6][7], lymphocytes [8,9], yeast cells [10] to plant protoplasts [11]. The electrical characterization of the erythrocyte cell membrane has been generally developed on the basis of different models, at a different degree of complexity, involving spherical [12] or ellipsoidal shaped particle models [13,14].…”