Referenced in: none

Automatically associated channels: ClC4 , ClC5

Title: Novel outwardly rectifying anion conductance in Xenopus oocytes.

Authors: Juan P Reyes, Carmen Y Hernández-Carballo, Patricia Pérez-Cornejo, Ulises Meza, Ricardo Espinosa-Tanguma, Jorge Arreola

Journal, date & volume: Pflugers Arch., 2004 Dec , 449, 271-7

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15452709

Abstract
We describe a novel, strongly outwardly rectifying anion current in Xenopus laevis oocytes, that we have named I(Cl,Or)- The properties of I(Cl,Or) are different from those of any other anion conductance previously described in these cells. Typically, I(Cl,Or) amplitude was small when extracellular Cl- (Cle) was the permeant anion. However, when Cle was replaced by lyotropic anions I(Cl,Or) became evident as a time-independent current. (ICl,Or) was voltage dependent and showed a remarkable outwards rectification with little or no inwards tail current. The relative selectivity sequence determined from current amplitudes was: SCN- > or = ClO4- > I- > Br- > or = NO3- > Cl- x I(Cl,Or) was insensitive to Gd3+ but was blocked by micromolar concentrations of niflumic acid, DIDS or Zn2+. Furthermore, I(Cl,Or) was not affected by buffering intracellular Ca2+ with BAPTA. Low extracellular pH inhibited I(Cl,Or) with a pK of 5.8. We propose that I(Cl,Or) might result from activation of endogenous ClC-5-like Cl- channels present in Xenopus oocytes.