The Electrical Charge of Mammalian Red Blood Cells

Abramson, Harold A.; Moyer, Laurence S.

doi:10.1085/jgp.19.4.601

Cited by 51 publications

(20 citation statements)

References 8 publications

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“…lowest pH was 1.0 #/sec./volt/cm., and did not appear to change during several minutes following hemolysis. (Similar mobility reversals on hemolysis in acid solutions had formerly been observed by Abramson (1930) with sheep cells.) (b) A decrease of the negative mobility of intact red cells with time also occurs when the suspending solution is a mixture of 97.5 parts of 5.4 per cent glucose and 2.5 parts of the standard saline-phosphate solution.…”

Section: Variations In Mobility Under Certain Conditionssupporting

confidence: 82%

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Electrophoretic Studies on Human Red Blood Cells

Furchgott

Ponder

1941

Journal of General Physiology

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These experiments were made to obtain more information about the surface of the red blood cell. Since "surface" means different things to different people, we shall define our meaning now. Strictly speaking, the surface studied by electrophoresis is the surface of shear between the cell (moving in the electric field) and the surrounding medium, for it is the potential at this surface which is the electrokinetic potential. But since this potential has its origin in the charged groups possessed by the cell membrane, we shall broadly use the term surface (unless we say otherwise) to mean that part of the membrane possessing these charged groups. That part of the membrane may be limited to the outermost constituent molecules of the membrane (i.e., to those molecules just inside the surface of shear), but we have no direct evidence of this. Also we have no data on the variations of charge density in different portions of the surface.The electrophoresis studies in this paper are divided into three parts. First, we have determined the mobility of human red cells as a function of the ionic strength at approximately constant pH. Secondly, we have determined the mobility as a function of p H at constant ionic strength for intact red cells, for the lipid of the red cell stroma, and for the protein of the stroma. Finally, we have determined the mobility of cells and ghosts under experimental conditions which cause changes in the mobility. Methods and Preparations 1. Method of Electrophoresis.--The mobility measurements were carried out in anAbramson horizontal mieroelectrophoresis cell, using the technique of Abramson (1929Abramson ( , 1934 and of Moyer (1936). The cell was modified in two respects. The horizontal observation chamber dipped slightly below the level of the stopcocks and glass supporting rods, so that it rested on the microscope stage just above the condenser. This made it possible to use the cell with dark-field illumination (paraboloid) as well as with direct light. With direct light a Zeiss 28x ocular and 40x water-immersion objective were used, while with dark-field illumination we used the same ocular and a 20x high-dry objective. In the mobility measurements direct illumination was used except when specifically stated.The other modification of the cell was the shortening of the vertical outlet tube over 447

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Section: Variations In Mobility Under Certain Conditionssupporting

confidence: 82%

“…These changes in mobility with time, which may be due to adsorption of proteins (possibly hemoglobin where hemolysis is occurring) on the cell surface at low pH levels, have led to the reporting of wrong isoelectric points for red cells. Abramson (1930) has previously discussed this matter in some detail.…”

Section: Discussionmentioning

confidence: 99%

Electrophoretic Studies on Human Red Blood Cells

Furchgott

Ponder

1941

Journal of General Physiology

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“…Further corrections for radius of curvature (as previously discussed) would place these groups somewhat closer together. Using Abramson and Moyer's assumption that an ion occupies an area of about 1 X 10 -'1 cm 2 (30), approximately 0.6% of the total cell surface would be negatively charged under these conditions. This calculation, of course, does not take into account the fact that there may be charged groups below the electrophoretic surface of shear; these groups may be numerous, and may be of importance in determining the permeability properties of the cell, yet they would not contribute to electrophoretic mobility.…”

Section: Discussionmentioning

confidence: 99%

The Surface Charge of Isolated Toad Bladder Epithelial Cells

Lipman

Dodelson

Hays

1966

The Journal of General Physiology

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The surface charge of epithelial cells isolated from the toad bladder has been determined by the microscope method of cell electrophoresis. The cells possess a net negative charge, and a net surface charge density of 3.6 X 10' electronic charges per square micron at pH 7.3. Estimates of net surface charge over the alkaline pH range indicate (a) that an average distance of the order of 40 A separates the negatively charged groups, and (b) that amino as well as acid groups are present at the electrophoretic surface of shear. A significant increase in mobility following cyanate treatment of the cells suggests that a large proportion of the amino groups are the e-amino groups of lysine. In view of the known effects of calcium and other divalent ions on cell permeability and cell adhesion, the extent of binding of calcium and magnesium to the cell surface was determined by the electrophoretic technique. Mobility was significantly decreased in the presence of calcium or magnesium, indicating that these ions are bound by surface groups. When the pH was lowered from 7.3 to 5.2, calcium binding was markedly decreased, an observation consistent with competition between calcium and hydrogen ions for a common receptor site.

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“…First, let us consider the charge on the outside of the membrane. Abramson and Moyer (45) have shown from mobility measurements that the red cell in man has an approximate zeta potential of --16.8 my., which they have calculated to be equal to 15 million excess electrons on each red cell. They further estimate that about 1 per cent of the red cell surface is occupied by these 15 million electrons.…”

Section: The Cation Barrier In the Red Cell Membrane-mentioning

confidence: 99%

The Permeability of the Human Erythrocyte to Sodium and Potassium

Solomon

1952

Journal of General Physiology

245

111

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The present experiments have been undertaken to measure the permeability of the human erythrocyte to sodium and potassium; to determine the temperature coefficient of these two permeabilities; and to investigate the relationship between external concentration of sodium and potassium and their relative permeabilities. In addition, thermodynamic constants of these two processes have been measured where possible. It is in all cases desirable to make experimental observations when the cell is in a steady state, so t h a t the system remains as independent as possible of the disturbance caused by the observation. The radioactive isotopes of sodium and potassium, Na ~4 and K s, are admirably adapted for studies of this nature, as has been previously pointed out by Raker, Taylor, Weller, and Hastings (1) and Sheppard, Martin, and Beyl (2-4) in their studies on the permeability of the human erythrocyte to these elements. I E~cperimental MethodThe experiments were carried out with fresh heparinized whole blood to which the necessary small quantities of isotonic solutions of glucose, Na~*C1, and KaCI were added. In some cases, the blood was diluted with a buffer of the composition given in Table I as used by Raker et al., except for the addition of glucose. In cases in which the effect of Na concentration was studied, isotonic sucrose (or melezitose or raffinose) with the requisite admixture of isotonic NaC1 (or other chlorides) served as diluent. For the K studies, the cells were incubated in a shaker under 3 per cent CO, (with oxygen or air) at temperatures in the neighborhood of 37°C. for periods of 4 hours. For the Na studies, the incubation continued for 10 or 12 hours. The incubation vessels were especially designed to keep the whole system including the vapor phase under the surface of the water bath. The gas mixture was saturated with water vapor first at room temperature by flowing through a bubbler filled with water at room temperature, and second at bath temperature by passing through another bubbler which was totally immersed under the surface of the bath. The gas did not emerge above the surface of the bath until it was exhausted from the reaction chamber. These precautions were sufficient to insure that the blood did not gain or lose any water, as indicated by measurements of the Na and K concentrations of the blood 57

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The Electrical Charge of Mammalian Red Blood Cells

Cited by 51 publications

References 8 publications

Electrophoretic Studies on Human Red Blood Cells

Electrophoretic Studies on Human Red Blood Cells

The Surface Charge of Isolated Toad Bladder Epithelial Cells

The Permeability of the Human Erythrocyte to Sodium and Potassium

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