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 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.

Proton-sulfate cotransport: external proton activation of sulfate influx into human red blood cells

1984 ◽  
Vol 247 (3) ◽  
pp. C247-C259 ◽  
Author(s):  
M. A. Milanick ◽  
R. B. Gunn
Keyword(s):  
Membrane Potential ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Half Cycle ◽  
Ph Values ◽  
Human Red Blood Cells ◽  
Internal Ph ◽  
Ph Range ◽  
External Ph ◽  
Chloride Concentrations

Sulfate influx into human red blood cells was measured at 0 and 22 degrees C at several fixed external pH values between 3 and 10. These cells had normal internal pH and chloride concentrations so that sulfate influx was not limited by the efflux half-cycle reactions. The flux was a Michaelis-Menten function of sulfate concentration at each pH with K1/2SO4 = 4-10 mM. External protons activated influx 100-fold at a single site with a pK = 5.9 at 22 degrees C and 5.5 at 0 degrees C. This pK is similar to the value 5.99 +/- 0.3 for external proton binding to the sulfate-loaded transporter at 0 degrees C (J. Gen. Physiol. 79: 87-114, 1982). The flux was stilbene sensitive even in valinomycin-treated cells and was independent of membrane potential. This proton-activated influx appears to be proton-sulfate cotransport. At high pH there was a proton-independent flux that was membrane potential and stilbene sensitive. This proton-insensitive flux appears to be SO4(2-)/Cl- exchange or net sulfate influx. The sulfate influx over the entire pH range may be described in terms of an equation for the sum of the influxes through these two pathways on band 3.

scholarly journals Volume regulation by Amphiuma red blood cells. The membrane potential and its implications regarding the nature of the ion-flux pathways.

1980 ◽  
Vol 76 (6) ◽  
pp. 683-708 ◽  
Author(s):  
P M Cala
Keyword(s):  
Membrane Potential ◽  
Alkali Metal ◽  
Red Blood Cells ◽  
Cell Volume ◽  
Blood Cells ◽  
Volume Regulation ◽  
Regulatory Volume Decrease ◽  
Cell Volume Regulation ◽  
Ion Flux ◽  
Regulatory Response

After osmotic perturbation, the red blood cells of Amphiuma exhibited a volume-regulatory response that returned cell volume back to or toward control values. After osmotic swelling, cell-volume regulation (regulatory volume decrease; RVD) resulted from net cellular loss of K, Cl, and osmotically obliged H2O. In contrast, the volume-regulatory response to osmotic shrinkage (regulatory volume increase; RVI) was characterized by net cellular uptake of Na, Cl, and H2O. The net K and Na fluxes characteristic of RVD and RVI are increased by 1-2 orders of magnitude above those observed in studies of volume-static control cells. The cell membrane potential of volume-regulating and volume-static cells was measured by impalement with glass microelectrodes. The information gained from the electrical and ion-flux studies led to the conclusion that the ion fluxes responsible for cell-volume regulation proceed via electrically silent pathways. Furthermore, it was observed that Na fluxes during RVI were profoundly sensitive to medium [HCO3] and that during RVI the medium becomes more acid, whereas alkaline shifts in the suspension medium accompany RVD. The experimental observations are explained by a model featuring obligatorily coupled alkali metal-H and Cl-HCO3 exchangers. The anion- and cation-exchange pathways are separate and distinct yet functionally coupled via the net flux of H. As a result of the operation of such pathways, net alkali metal, Cl, and H2O fluxes proceed in the same direction, whereas H and HCO3 fluxes are cyclic. Data also are presented that suggest that the ion-flux pathways responsible for cell-volume regulation are not activated by changes in cell volume per se but by some event associated with osmotic perturbation, such as changes in intracellular pH.

scholarly journals Direct estimate of 1:1 stoichiometry of K+-Cl−cotransport in rabbit erythrocytes

2001 ◽  
Vol 281 (3) ◽  
pp. C825-C832 ◽  
Author(s):  
Michael L. Jennings ◽  
Mark F. Adame
Keyword(s):  
Membrane Potential ◽  
Red Blood Cells ◽  
Okadaic Acid ◽  
Blood Cells ◽  
Model System ◽  
Disulfonic Acid ◽  
Calyculin A ◽  
Direct Measure ◽  
Direct Estimate ◽  
Exchange Flux

This work was undertaken to obtain a direct measure of the stoichiometry of Na+-independent K+-Cl−cotransport (KCC), with rabbit red blood cells as a model system. To determine whether86Rb+can be used quantitatively as a tracer for KCC,86Rb+and K+effluxes were measured in parallel after activation of KCC with N-ethylmaleimide (NEM). The rate constant for NEM-stimulated K+efflux into isosmotic NaCl was smaller than that for86Rb+by a factor of 0.68 ± 0.11 (SD, n = 5). This correction factor was used in all other experiments to calculate the K+efflux from the measured86Rb+efflux. To minimize interference from the anion exchanger, extracellular Cl−was replaced with SO[Formula: see text], and 4,4′-diisothiocyanothiocyanatodihydrostilbene-2,2′-disulfonic acid was present in the flux media. The membrane potential was clamped near 0 mV with the protonophore 2,4-dinitrophenol. The Cl−efflux at 25°C under these conditions is ∼100,000-fold smaller than the uninhibited Cl−/Cl−exchange flux and is stimulated ∼2-fold by NEM. The NEM-stimulated36Cl−flux is inhibited by okadaic acid and calyculin A, as expected for KCC. The ratio of the NEM-stimulated K+to Cl−efflux is 1.12 ± 0.26 (SD, n = 5). We conclude that K+-Cl−cotransport in rabbit red blood cells has a stoichiometry of 1:1.

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.

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