Functional characterization of a voltage-gated anion channel from teleost fish intestinal epithelium.

An anion channel was isolated, using patch-clamp technique, from the basolateral membrane of goby intestinal epithelial cells. Single-channel conductance varied over a range from 20 to 90 pS. The channel was voltage-gated over the physiological range of cell membrane potential with depolarization increasing the proportion of time in the open state. There was no Ca2+ sensitivity. The selectivity sequence was SO4(2-) greater than Cl- greater than Mes-. The channel may function in vivo as one of several avenues of basolateral membrane Cl- exit with the voltage-gating property serving to match basolateral Cl- exit to apical entry.