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Pharmacology of the human red cell voltage-dependent cation channel. Part II: inactivation and blocking
- Source :
- Blood Cells, Molecules, and Diseases. 33:356-361
- Publication Year :
- 2004
- Publisher :
- Elsevier BV, 2004.
-
Abstract
- Pharmacological modulation of the nonselective voltage-dependent cation (NSVDC) channel from human erythrocytes was studied. Using the inorganic cations ruthenium red and La3+, as well as the organic thiol group reagents iodoacetamide (IAA) and N-ethylmaleimide (NEM), it was possible to demonstrate a concentration-dependent decrease in the voltage-activated conductance, reflecting an inhibition or inactivation of the channel. Initial voltage activation was achieved by injecting human red cells into sucrose-substituted Ringers with a low chloride concentration, which causes a strongly positive membrane potential to develop, initially determined by the equilibrium potential for Cl- ( approximately +100 mV). Due to the voltage- and time-dependent activation of the cation channel, net effluxes, minimized by addition of a chloride conductance blocker, occurred and Vm gradually decreased and stabilized at a value less positive than E(Cl), reflecting the increased cation conductance, g+, reaching 1.5-2.0 microS/cm2. In the presence of inhibitors of the NSVDC channel, both the membrane potential repolarization and the cation efflux were diminished.
- Subjects :
- Ruthenium red
Chloride
Ion Channels
Membrane Potentials
Iodoacetamide
chemistry.chemical_compound
Lanthanum
Cations
medicine
Humans
Repolarization
Coloring Agents
Molecular Biology
Membrane potential
Dose-Response Relationship, Drug
Red Cell
Erythrocyte Membrane
Sulfhydryl Reagents
Conductance
Cell Biology
Hematology
Ruthenium Red
chemistry
Biochemistry
Ethylmaleimide
Biophysics
Molecular Medicine
Efflux
Ion Channel Gating
medicine.drug
Subjects
Details
- ISSN :
- 10799796
- Volume :
- 33
- Database :
- OpenAIRE
- Journal :
- Blood Cells, Molecules, and Diseases
- Accession number :
- edsair.doi.dedup.....f4cc804699c15d3f4c64d5a591d4443d