Pharmacology of the human red cell voltage-dependent cation channel. Part II: inactivation and blocking
| Autor: | Lars R. Jensen, Trine L. Barksmann, Berit I. Kristensen, Poul Bennekou, Palle Christophersen |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
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 |
| Zdroj: | Blood Cells, Molecules, and Diseases. 33:356-361 |
| ISSN: | 1079-9796 |
| DOI: | 10.1016/j.bcmd.2004.07.001 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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