scholarly journals Dog red blood cells: Na and K diffusion potentials with extracellular ATP.

1977 ◽  
Vol 69 (4) ◽  
pp. 417-430 ◽  
Author(s):  
J C Parker ◽  
V Castranova ◽  
J M Goldfinger
Keyword(s):  
Membrane Potential ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Ion Composition ◽  
Chloride Permeability ◽  
A Value ◽  
Diffusion Potentials ◽  
Rough Calculation ◽  
K Permeability ◽  
Net Fluxes

External ATP causes a prompt increase in the Na and K permeability of dog red blood cells. By manipulating intra- and extracellular ion composition it is possible to observe ATP-induced net fluxes which can be explained in terms of the contribution of Na or K diffusion potentials to the membrane potential. Measurements of membrane voltage by a fluorescent dye technique confirm the existence of such potentials. A rough calculation of chloride permeability gives a value of the order of 10(-8) cm/s, which agrees with results in other species. The cells appear to be somewhat more permeable to bromide than to chloride.

scholarly journals The relation between dicarbocyanine dye fluorescence and the membrane potential of human red blood cells set at varying Donnan equilibria.

1979 ◽  
Vol 74 (2) ◽  
pp. 187-212 ◽  
Author(s):  
J C Freedman ◽  
J F Hoffman
Keyword(s):  
Membrane Potential ◽  
Fluorescence Quenching ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Red Cell Membrane ◽  
Human Red Blood Cells ◽  
Fluorescence Measurements ◽  
Constant E ◽  
Diffusion Potentials ◽  
Dye Fluorescence

The fluorescence, F, of two dicarbocyanine dyes, diS-C3(5) and diI-C3(5), depends both on the membrane potential, E, and on the intracellular pH, pHc, or human red blood cells. Compositions of isotonic media have been devised in which the equilibrium Donnan potential, E, varies at constant pHc and in which pHc varies at constant E. Dye fluorescence measurements in these suspensions yield calibrations of +1.7 % delta F/mV for diS-C3(5) and +0.6 % delta F/mV for diI-C3 (5). While pHo does not affect F of either dye, changes in pHc of 0.1 unit at constant E cause changes of F equivalent to those induced by 2--3mV. Based on these results, a method is given for estimating changes in E from dye fluorescence in experiments in which E and pHc co-vary. The relation of F to E also depends in a complex way on the type and concentration of cells and dye, and the wavelengths employed. The equilibrium calibration of dye fluorescence, when applied to diffusion potentials induced by 1 microM valinomycin, yields a value for the permeability ratio, PK.VAL/PCl, of 20 +/- 5, in agreement with previous estimates by other methods. The calibration of F is identical both for diffusion potentials and for equilibrium potentials, implying that diC-C3(5) responds to changes in voltage independently of ionic fluxes across the red cell membrane. Changes in the absorption spectra of dye in the presence of red cells in response to changes in E show that formation of nonfluorescent dimers contributes to fluorescence quenching of diS-C3(5). In contrast, only a hydrophobic interaction of dye monomers need be considered for diI-C3(5), indicating the occurrence of a simpler mechanism of fluorescence quenching.

Mechanism by which cyanine dyes measure membrane potential in red blood cells and phosphatidylcholine vesicles

Biochemistry ◽  
1974 ◽  
Vol 13 (16) ◽  
pp. 3315-3330 ◽  
Author(s):  
Peter J. Sims ◽  
Alan S. Waggoner ◽  
Chao-Huei Wang ◽  
Joseph F. Hoffman
Keyword(s):  
Membrane Potential ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Cyanine Dyes ◽  
Measure Membrane Potential

scholarly journals A Hundred-Year Researching History on the Low Ionic Strength in Red Blood Cells: Literature Review

2021 ◽  
Vol 2 (3) ◽  
pp. 139-168
Author(s):  
GF Fuhrmann ◽  
KJ Netter
Keyword(s):  
Membrane Potential ◽  
Ionic Strength ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Sucrose Solution ◽  
Critical Survey ◽  
Unequal Distribution ◽  
Donnan Equilibrium ◽  
Disulfonic Stilbene ◽  
Low Ionic Strength

This review article provides a critical survey of work from 1904 to 2003 on the effects of low ionic strength in Red Blood Cells (RBCs) incubated in media with impermeable sugars such as sucrose. In 1904 Gürber A washed RBCs of different species with isotonic sucrose solution to eliminate the outside ions in order to better analyse their intracellular ionic composition; however, this approach was not feasible because of a substantial salt efflux from the cells. A prominent feature of the salt loss is the shrinking of the RBCs. A central role in the understanding of the ionic movements is thereby the new Donnan equilibrium of the anions. Experimental evidence has been given by Jacobs MH and Parpart AK in 1933. In the sucrose medium two phases could be predicted: 1) a very rapid anionic shift resulting in an unequal distribution of chloride and hydroxyl anions on both sides of the membrane and 2) a leakage of salts from the RBCs. In 1940 Wilbrandt W assumed that a positive membrane potential is in line with the salt loss at low ionic strength in RBCs. In 1977 Knauf PA, Fuhrmann GF, Rothstein S and Rothstein A observed in RBCs an inhibition of both, anion exchange and also of net anion efflux, by incubation with disulfonic stilbene derivates. At low ionic strength the Donnan equilibrium is immediately obtained by the Anion Exchanger Protein (AEP). The resulting positive membrane potential opens at least two new types of cation pores or channels. Thereby is the conductivity pathway for the anions, namely the AEP, in charge of the net anion loss at low ionic strength. The AEP pathway is extensively blocked by disulfonic stilbene compounds. The permeability ways for cations through these pores or channels are not yet explored.

scholarly journals Heterogeneity in dog red blood cells: sodium and potassium transport.

1979 ◽  
Vol 73 (1) ◽  
pp. 61-71 ◽  
Author(s):  
V Castranova ◽  
J F Hoffman
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Cell Types ◽  
Red Cells ◽  
Cell Type ◽  
Volume Dependence ◽  
Single Cell Type ◽  
Cell Volumes ◽  
K Permeability ◽  
Sodium And Potassium

After incubation in isotonic KCl, dog red blood cells can be separated by centrifugation into subgroups which assume different cell volumes and possess different transport characteristics. Those red cells which swell in isotonic KCl exhibit a higher permeability to K and possess a greater volume dependence for transport of K than those red cells which shrink. A high Na permeability characterizes cells which shrink in isotonic KCl and these cells exhibit a larger volume-dependent Na flux than those red cells which swell. These two subgroups of red cells do not seem to represent two cell populations of different age. The results indicate that the population of normal cells is evidently heterogeneous in that the volume-dependent changes in Na and K permeability are distributed between differnt cell types rather than representing a single cell type which reciprocally changes its selectivity to Na and K.

Threshold shear stress for the transition between tumbling and tank-treading of red blood cells in shear flow: dependence on the viscosity of the suspending medium

2013 ◽  
Vol 736 ◽  
pp. 351-365 ◽  
Author(s):  
Thomas M. Fischer ◽  
Rafal Korzeniewski
Keyword(s):  
Shear Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Theoretical Models ◽  
Red Cells ◽  
Theoretical Modelling ◽  
Glass Capillary ◽  
Basic Model ◽  
A Value ◽  
The Subject

AbstractRed blood cells are the subject of diverse studies. One branch is the observation and theoretical modelling of their behaviour in a shear flow. This work deals with the flow of single red cells suspended in solutions much more viscous than blood plasma. Below a critical shear rate (${\dot {\gamma } }_{t} $) the red cells rotate with little change of their resting shape. Above that value they become elongated and aligned in the shear field. We measured${\dot {\gamma } }_{t} $at viscosities (${\eta }_{0} $) ranging from 10.7 to 104 mPa s via observation along the vorticity of a Poiseuille flow in a glass capillary;${\eta }_{0} {\dot {\gamma } }_{t} $decreased steeply with increasing${\eta }_{0} $up to a value of 25 mPa s and remained constant for higher values. Present theoretical models are not in keeping with the measured data. Modifications of basic model assumptions are suggested.

scholarly journals Volume-responsive sodium and proton movements in dog red blood cells.

1984 ◽  
Vol 84 (3) ◽  
pp. 379-401 ◽  
Author(s):  
J C Parker ◽  
V Castranova
Keyword(s):  
Membrane Potential ◽  
Red Blood Cells ◽  
Fluorescent Probe ◽  
Blood Cells ◽  
Indirect Method ◽  
Cell Types ◽  
The Other ◽  
Na Transport ◽  
Transport Pathway ◽  
Transport Pathways

Shrinkage of dog red blood cells (RBC) activates a Na transport pathway that is Cl dependent, amiloride sensitive, and capable of conducting Na-proton counterflow. It is possible to establish transmembrane gradients for either Na or protons and to demonstrate that each cation species can drive reciprocal movements of the other. The nature of the coupling between Na and proton movements was investigated using the fluorescent probe diS-C3(5) and also by an indirect method in which K movements through valinomycin channels were used to draw inferences about the membrane potential. No evidence was found to suggest that the Na-proton pathway activated by shrinkage of dog RBC is a conductive one. By exclusion, it is presumed that the coupling between the counterflow of Na and protons is electroneutral. The volume-activated Na-proton fluxes in dog RBC have certain properties that distinguish them from similar transport pathways in other cell types.

scholarly journals Hormonal modulation of ionic permeability in human red blood cells.

1993 ◽  
Vol 3 (9) ◽  
pp. 1607-1612
Author(s):  
R D London ◽  
L Berson ◽  
M S Lipkowitz
Keyword(s):  
Parathyroid Hormone ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Hormone Receptors ◽  
Intracellular Camp ◽  
Chloride Permeability ◽  
Sodium Permeability ◽  
Human Red Blood Cells ◽  
Hormonal Modulation ◽  
Induced Changes

It has previously been reported that both exogenous adenosine cAMP analogs and forskolin-induced elevations in intracellular cAMP concentrations selective increase relative ionic chloride permeability in normal human red blood cells (RBC). A similar selectively increase in relative ionic chloride permeability was observed in untreated uremic subjects in whom endogenous RBC cAMP concentrations are chronically elevated. To detect which hormones might modulate RBC cAMP and ionic permeabilities, RBC were exposed to norepinephrine, epinephrine, and parathyroid hormone. Thereafter, RBC cAMP concentrations were measured by RIA and relative ionic permeabilities were determined in human RBC ghosts with the potential sensitive fluorescent probe diS-C3-(5). In ghosts prepared from normal RBC, norepinephrine and epinephrine significantly increased intracellular cAMP concentrations; in these ghosts, relative ionic chloride permeability (permeability of chloride/permeability of potassium (PCI/PK)), but not PNa/PK (permeability of sodium/permeability of potassium), was significantly increased. In contrast, exposure to parathyroid hormone did not affect either cAMP concentrations or relative ionic permeabilities. These results are consistent with the presence of adrenergic receptors and the absence of parathyroid hormone receptors in RBC. These studies demonstrate that hormonally induced changes in cAMP can modulate RBC relative ionic chloride permeability and suggest that, in uremic RBC, increased relative ionic chloride permeability could be consequent to elevated plasma levels of epinephrine or norepinephrine.

Production of ornithine by intact human erythrocytes

1982 ◽  
Vol 242 (5) ◽  
pp. C393-C397 ◽  
Author(s):  
J. A. Williams ◽  
J. M. Phang
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Incubation Medium ◽  
Human Erythrocytes ◽  
Arginine Metabolism ◽  
Close Approximation ◽  
Peripheral Tissues ◽  
A Value ◽  
Arginine Concentration ◽  
Release Product

Although the conversion of arginine to ornithine in humans is largely an hepatic process, erythrocytes also have this enzymatic capacity. We have shown that intact human erythrocytes readily produce ornithine from arginine and release product ornithine to the incubation medium. The rate of ornithine formation from arginine was 0.22 mumol.h-1.ml cells-1, and 85% of the ornithine is recovered extracellularly. Moreover, we have shown that ornithine and urea are the unique and stoichiometric products of arginine metabolism in the intact erythrocyte. The rate of ornithine production by intact red blood cells was a saturable function of arginine concentration in the medium; the derived Km for arginine for this conversion was 0.16 mM, a value striking for its close approximation to physiological arginine concentration in human plasma. We propose that the production and delivery of ornithine by intact red blood cells may supply peripheral tissues such as bone and muscle with an important precursor for proline and polyamines.

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