Referenced in: none

Automatically associated channels: ClC2 , ClC3 , ClC4

Title: Functional and molecular characterizations of chloride channels in rat pleural mesothelial cells.

Authors: Yuya Yoshise, Koichi Ito, Hirokazu Tsubone, Masayoshi Kuwahara

Journal, date & volume: Eur. J. Pharmacol., 2009 Jul 1 , 614, 22-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/19446550

Abstract
The purposes of the present study were to clarify whether some Cl(-) channels exist in rat pleural mesothelial cells, and to investigate functional and molecular characteristics of these channels. Electrophysiological recordings were performed at room temperature using the whole-cell configuration of the patch-clamp technique. We could observe outwardly rectifying Cl(-) currents in rat pleural mesothelial cells under isotonic conditions. These currents exhibited time-dependent inactivation at potential over +60 mV and were inhibited by NPPB. It suggests the presence of voltage-dependent Cl(-) channels. Moreover, we observed the currents activated under hypotonic conditions. Their biophysical and pharmacological properties exhibited as follows; moderate outward rectification of whole-cell currents; time-dependent inactivation at large positive potential; anion selectivity with a type-I Eisenman's permeability sequence (I(-)>Br(-)>Cl(-)>F(-)>glutamate(-)); inhibited by NPPB. These properties are consistent with volume-regulated chloride channels (VRCCs), even though molecular identity of VRCCs could not have been determined, the molecular expressions of mRNA of the Cl(-) channels ClC-2, ClC-3, pI(Cln), MDR1 were confirmed. The properties of VRCCs in the pleural mesothelial cells were consistent with those of ClC-3 channels, and different from those of ClC-2. Therefore, these results suggest that ClC-3 might contribute to the modulation of VRCCs in rat pleural mesothelial cells.