Volume Expansion Sensitivity of Swelling-Activated Cl⁻ Channel in Human Epithelial Cells

Abstract

In human epithelial cell lines, whole-cell swelling-activated Cl⁻ current was not directly correlated to cell volume per se, membrane tension or hydrostatic pressure. The current density exhibited a relation described by a Boltzmann function to the square of the cell diameter. Cytochalasin D enhanced the volume sensitivity. These results suggest that the activation mechanism of volume-sensitive Cl⁻ channel is related to cytoskeleton-dependent membrane spring energy in human epithelial cells.