Membrane and cytoplasmic resistivity properties of normal and sickle red blood cells

Abstract

The cytoplasmic resistivities and membrane breakdown potentials of normal (AA), sickle-cell-trait (AS), as sickle (SS) red blood cells have been measured by the biophysical methodology of resistive pulse spectroscopy over a range of osmolalities. At isotonicity, the average membrane breakdown potentials are virtually identical for the three types of cells occurring at about 1150 V/cm. Average isotonic cytoplasmic resistivities are somewhat higher for the SS cells (166.7 +/- 7.49 ohm-cm) compared to the AA (147.6 +/- 1.98 ohm-cm) or AS cells (148.7 +/- 1.79 ohm-cm). As medium osmolality is varied, the differences in resistive properties become enlarged, especially at very low and very high osmolalities. At high osmolalities, both types of sickle cells show a large increase in internal resistivity compared to the normals; at low osmolality, the SS samples exhibit a distinctly different membrane breakdown characteristic, decreasing in this parameter, whereas the other two groups increase. Of the 15 SS samples tested, three displayed much higher cytoplasmic resistivities at isotonicity: 218.2 +/- 5.25 ohm-cm, compared to an average of 153.5 +/- 3.46 ohm-cm for the other 12. The relationship between these high resistivities and the subfraction of irreversibly sickled cells in the sample is discussed.

Influence of divalent cations Ca2+ and Zn2+ on the activation of posthypertonic hemolysis of human erythrocytes

“…The distribution of cell volumes in the samples was measured using a Coulter-type apparatus with an orifice 50 μχη long * 5 μ\Ά in diameter [12,13] using a current < 0,3 mA. 2-Ю' 5 cells were sampled in each measurement and the mean linear velocity through the orifice was < 1 m/sec: the cells were not significantly deformed [12].…”

A study of the dynamics of volume changes during the period of active motility in carp,Cyprinus carpioL., spermatozoa

“…Changes in the volume and concentration of spermatozoa were measured with an ECA‐1 electrocytoanalyser (Ukraine, Kharkov, Small Scientific Production Enterprise ‘‘TIMEL’') [similar to the Coulter Counter type devices (Richery & Mel 1986)]. The principle of the device and its operation is based on the recording of electrical impulses, appearing when a cell is passing through the counter channel.…”