Contribution of chloride channel conductance to the regulation of resting membrane potential in chondrocytes

Abstract

The contribution of Cl-1 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 μM niflumic acid (NFA) and other anion-channel blockers induced significant membrane hyperpolarization. The NFA-sensitive membrane current under voltage-clamp was predominantly Cl-1 current. Application of NFA induced small but significant increase in intracellular Ca2+ concentration ([Ca2+]i) and markedly enhanced the late component of [Ca2+]i rise induced by 1 μM histamine. In conclusion, Cl-1 conductance substantially contributes to the regulation of resting membrane potential and [Ca2+]i in OUMS-27 cells. © 2010 The Japanese Pharmacological Society.