Contribution of chloride channel conductance to the regulation of resting membrane potential in chondrocytes.
The contribution of Cl(-) conductance relative to that of K(+) in the regulation of membrane potential was examined using OUMS-27 cells, a model cell-line of human chondrocytes. Application of 100 microM niflumic acid (NFA) and other anion-channel blockers induced significant membrane hyperpolarization. The NFA-sensitive membrane current under voltage-clamp was predominantly Cl(-) current. Application of NFA induced small but significant increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) and markedly enhanced the late component of [Ca(2+)](i) rise induced by 1 microM histamine. In conclusion, Cl(-) conductance substantially contributes to the regulation of resting membrane potential and [Ca(2+)](i) in OUMS-27 cells.
Funabashi
Kenji
K
Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Japan.
Fujii
Masato
M
Yamamura
Hisao
H
Ohya
Susumu
S
Imaizumi
Yuji
Y
D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D009544:Niflumic Acid / Q000494:pharmacology
D018118:Chloride Channels; D009544:Niflumic Acid; D006632:Histamine; D002118:Calcium