mRNA encoding 'ClC-K1, a kidney Cl(-)- channel' is expressed in marginal cells of the stria vascularis of rat cochlea: its possible contribution to Cl(-) currents.
The cochlear stria vascularis is essential for the normal function of hair cells. mRNA encoding the ClC-K1 Cl(-) channel, previously thought to be found only in the kidney, was detected in epithelial marginal cells of the rat stria vascularis by single cell RT-PCR. When Cl(-) currents were recorded from rat marginal cells by the whole-cell patch clamp method, the steady-state currents showed weak outward rectification and an ion selectivity sequence of SCN(-)Br(-)=Cl(-)F(-)NO(3)(-)I(-)gluconate(-). The Cl(-) currents were regulated by extracellular Ca(2+) and pH. These characteristics resemble those reported for the currents recorded from Xenopus oocytes expressing ClC-K1 Cl(-) channels. These data together suggest that ClC-K1 Cl(-) channels may contribute to the whole-cell currents of marginal cells.
Ando
M
M
Department of Physiology, Kochi Medical School, Nankoku, Japan.
Takeuchi
S
S
D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D018118:Chloride Channels / Q000235:genetics* / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D004553:Electric Conductivity; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D015640:Ion Channel Gating / Q000187:drug effects; D007668:Kidney / Q000737:chemistry*; D009994:Osmolar Concentration; D018408:Patch-Clamp Techniques; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D051381:Rats; D011914:Rats, Inbred BN; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013316:Stria Vascularis / Q000166:cytology / Q000378:metabolism*; D013379:Substrate Specificity; D029867:Xenopus Proteins
D018118:Chloride Channels; D002712:Chlorides; C082118:Clcnka protein, rat; D012333:RNA, Messenger; D029867:Xenopus Proteins; C489934:clcnka protein, Xenopus; D002118:Calcium