Biomaterial Database

Investigations on the control of ion transport in human erythrocytes. II. Influence of transmembrane potential, exterior surface potential and intracellular pH on the 22Na efflux. 1982

I Bernhardt, and R Glaser

The rate constant of the Na+ efflux of human erythrocytes in isotonic solutions of various ionic strength varied over NaCl concentration was measured. The Na+ efflux remained constant over a wide range of ionic strength. Only under conditions where the transmembrane potential was near O mV, a local minimum could be detected. The rate constant of the ouabain-insensitive part of the Na+ efflux exhibited a strong increase at reduced exterior ionic strength. When reducing the extracellular NaCl concentration and at the same time equivalently increasing the extracellular KCl concentration in solutions of physiological ionic strength, a reduction of the rate constant of the Na+ efflux was found. It was established that an increase of the intracellular pH increases the rate constant of the Na+ efflux. A change of transmembrane potential from -7 to 52 mV at constant intracellular pH had no influence on the Na+ efflux. The change of the exterior surface potential of erythrocytes by preincubation with neuraminidase had no influence on the Na+ efflux in the range of the ionic strength studied.

UI	MeSH Term	Description	Entries
D007474	Ion Exchange	Reversible chemical reaction between a solid, often one of the ION EXCHANGE RESINS, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry.	Exchange, Ion
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D012975	Sodium Isotopes	Stable sodium atoms that have the same atomic number as the element sodium, but differ in atomic weight. Na-23 is a stable sodium isotope.	Isotopes, Sodium