In human epithelial cell lines, whole-cell swelling-activated Cl- current w
as not directly correlated to cell volume per se, membrane tension or hydro
static pressure. The current density exhibited a relation described by a Bo
ltzmann function to the square of the cell diameter. Cytochalasin D enhance
d the volume sensitivity, These results suggest that the activation mechani
sm of volume-sensitive Cl- channel is related to cytoskeleton-dependent mem
brane spring energy in human epithelial cells.