Difluorophosphate as a 19F NMR probe of erythrocyte membrane potential

1991 ◽  
Vol 19 (6) ◽  
Author(s):  
A.S.L. Xu ◽  
P.W. Kuchel
Keyword(s):  
Membrane Potential ◽  
Erythrocyte Membrane ◽  
19F Nmr

K+ transport across the lamprey erythrocyte membrane: characteristics of a Ba(2+)- and amiloride-sensitive pathway

1991 ◽  
Vol 159 (1) ◽  
pp. 303-324 ◽  
Author(s):  
K. Kirk
Keyword(s):  
Membrane Potential ◽  
Erythrocyte Membrane ◽  
Inhibitory Effect ◽  
Extracellular Ph ◽  
Transport Pathway ◽  
Full Effect ◽  
River Lamprey ◽  
K Concentration ◽  
86Rb Influx ◽  
K Transport

The characteristics of K+ transport in erythrocytes from the river lamprey (Lampetra fluviatilis) were investigated using standard radioisotope flux techniques. The cells were shown to have a ouabain-sensitive transport pathway that carried 43K+ and 86Rb+ into the cell at similar rates. Most of the ouabain-resistant 43K+ and 86Rb+ influx was via a pathway that was insensitive to cotransport inhibitors and to the replacement of extracellular Cl- or Na+. This pathway showed a strong selectivity for 43K+ over 86Rb+. It was inhibited fully by Ba2+ (I50 approximately 2.8 mumol l-1), amiloride (I50 approximately 150 mumol l-1) and ethylisopropylamiloride (I50 approximately 3.3 mumol l-1) and less effectively by quinine and by the tetraethylammonium ion. Inhibition by Ba2+ took full effect within a few minutes whereas the full inhibitory effect of amiloride took more than 1 h to develop. Experiments with the membrane potential probe [14C]tetraphenylphosphonium ion gave results consistent with the lamprey erythrocyte membrane having a Ba(2+)-sensitive K+ conductance that was significantly greater than the membrane Na+ conductance and which gave rise to a marked dependence of the membrane potential on the extracellular K+ concentration. The rate constants for Ba(2+)-sensitive 43K+ and 86Rb+ influx decreased (proportionally) with increasing extracellular K+ concentration in a manner that was consistent with the transport being via a conductive pathway. The decrease was attributed to a depolarisation of the membrane (in response to the increasing extracellular K+ concentration) and a consequent decrease in the driving force for the conductive movement of 43K+ and 86Rb+ into the cells. Ba(2+)-sensitive 86Rb+ influx increased significantly with decreasing cell volume and with increasing intracellular pH (at a constant extracellular pH) but increased only slightly with increasing extracellular pH. The pathway operated normally in the complete absence of extracellular Ca2+ but its activity decreased in cells pretreated with ionomycin and EGTA; this suggests a role for intracellular Ca2+ in the operation of the pathway.

Transport of hydrophobic ions in erythrocyte membrane: I. Zero membrane potential properties

1985 ◽  
Vol 84 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Andre Hunziker ◽  
Frank W. Orme ◽  
Robert I. Macey
Keyword(s):  
Membrane Potential ◽  
Erythrocyte Membrane ◽  
Hydrophobic Ions

Effect of membrane potential of fusion of sendai virus envelope with chick erythrocyte membrane and on virus-induced hemolysis

1988 ◽  
Vol 106 (6) ◽  
pp. 1748-1751
Author(s):  
V. A. Slepushkin ◽  
V. M. Chumakov ◽  
A. �. Kalmanson ◽  
S. M. Marchenko ◽  
A. G. Bukrinskaya
Keyword(s):  
Membrane Potential ◽  
Erythrocyte Membrane ◽  
Sendai Virus ◽  
Virus Envelope

scholarly journals Participation of reactive oxygen species in regulation of Са2+ - activated К + channels of erythrocytes

2009 ◽  
Vol 8 (2) ◽  
pp. 56-60
Author(s):  
O. A. Trubacheva ◽  
S. V. Kremeno ◽  
I. V. Petrova ◽  
A. V. Sitozhevsky ◽  
O. V. Gruzdeva ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Membrane Potential ◽  
Xanthine Oxidase ◽  
Erythrocyte Membrane ◽  
Calcium Ionophore ◽  
Reactive Oxygen ◽  
Significant Loss ◽  
Ionophore A23187 ◽  
Oxygen Species ◽  
Membrane Hyperpolarization

In this study, we investigated the effects of preincubation with the reactive oxygen species-generating system xanthine oxidase/xanthine on Ca2+-dependent potassium permeability of erythrocyte membrane. The increase of intracellular calcium concentration in presence of calcium ionophore A23187 led to erythrocyte membrane hyperpolarization due to opening of Ca2+-activated potassium channels. Erythrocyte membrane potential was recorded via measurement of pH of the incubation medium in presence of prothonophore. Incubation of erythrocytes with xanthine (100 µmol)/ xanthine oxidase (10 mU/ml) mixture resulted in significant loss of amplitude and rate of hyperpolarization response and also loss the rate of membrane potential restoration. These effects can be caused by hydrogen peroxide, one of products of reaction of xanthine oxidase/xanthine.

Further evidence for a membrane potential-dependent shape transformation of the human erythrocyte membrane

1986 ◽  
Vol 6 (11) ◽  
pp. 999-1006 ◽  
Author(s):  
Peter Müller ◽  
Andreas Herrmann ◽  
Roland Glaser
Keyword(s):  
Membrane Potential ◽  
Ionic Strength ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Transmembrane Potential ◽  
Sodium Gluconate ◽  
Human Erythrocyte Membrane ◽  
Shape Transformation

The influence of various factors (pH, temperature, sodium gluconate) on the ionic strength-dependent stomatocyte-discocyte-echinocyte transformation of the human erythrocyte membrane was investigated. The results give further evidence for a correlation between shape of erythrocyte membrane and the transmembrane potential of the cells.

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