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

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.