title: Activation by acidic pH of CLC-7 expressed in oocytes from Xenopus laevis.
abstract: ClC chloride channels are important in diverse physiological functions such as transepithelial transport, cell volume regulation, excitability, and acidification of intracellular organelles. We have investigated the expression of CLC-7 in oocytes from Xenopus laevis with the two electrode voltage clamp technique and Western blot analysis. Using a specific antibody against CLC-7, we found an approximately 80 kDa protein in oocytes, previously injected with CLC-7-cRNA. In voltage clamp experiments on ClC-7-cRNA-injected oocytes, no current changes were detected at normal pH (7.4). However, acidification of the Ringer solution to pH values between 6 and 4 revealed strong currents which reversed at about -15 mV (30 mV positive to the normal resting potential) and showed strong outward rectification. We therefore suggest that ClC-7 in oocytes is a functional chloride current at acidic pH. Since ClC-7 is also found in neuronal tissues and was upregulated in a rat pain model, we suggest a role of CLC-7 also for nociception and pain.
authors.affiliation: Pharmakologisches Institute der Universität Mainz, Mainz, Germany.
authors.forename: Linda
authors.initials: L
authors.lastname: Diewald
authors.forename: Johanna
authors.initials: J
authors.lastname: Rupp
authors.forename: Mathias
authors.initials: M
authors.lastname: Dreger
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Hucho
authors.forename: Clemens
authors.initials: C
authors.lastname: Gillen
authors.forename: Hermann
authors.initials: H
authors.lastname: Nawrath
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018118:Chloride Channels / Q000378:metabolism*; D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D009865:Oocytes / Q000378:metabolism; D018408:Patch-Clamp Techniques; D051381:Rats; D014982:Xenopus laevis
chemical_list: D018118:Chloride Channels; C490802:Clcn7 protein, rat