Referenced in: none

Automatically associated channels: Kv10.1

Title: Pharmacology of the human red cell voltage-dependent cation channel. Part II: inactivation and blocking.

Authors: Poul Bennekou, Trine L Barksmann, Berit I Kristensen, Lars R Jensen, Palle Christophersen

Journal, date & volume: Blood Cells Mol. Dis., 2004 Nov-Dec , 33, 356-61

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15528157

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.