Hyposmotic activation of ICl,swell in rabbit nonpigmented ciliary epithelial cells involves increased ClC-3 trafficking to the plasma membrane.

In mammalian nonpigmented ciliary epithelial (NPE) cells, hyposmotic stimulation leading to cell swelling activates an outwardly rectifying Cl(-) conductance (I(Cl,swell)), which, in turn, results in regulatory volume decrease. The aim of this study was to determine whether increased trafficking of intracellular ClC-3 Cl channels to the plasma membrane could contribute to the I(Cl,swell) following hyposmotic stimulation. Our results demonstrate that hyposmotic stimulation reversibly activates an outwardly rectifying Cl(-) current that is inhibited by phorbol-12-dibutyrate and niflumic acid.