Tetraethylammonium-insensitive, Ca(2+)-activated Whole-cell K+ Currents in Rat Submandibular Acinar Cells

Using whole-cell patch-clamp techniques, we demonstrate, for the first time, that rat submandibular acinar cells contain a tetraethylammonium (TEA)-insensitive, Ca(2+)-activated K+ conductance which is not attributable to large conductance, voltage-sensitive, Ca(2+)-dependent K+ channels (maxi-K+ channels). Taken together with our recent K+ efflux and fluid secretion studies in intact rat submandibular gland, we postulate that the K+ conductance reported here may be involved in the basolateral K+ efflux pathway activated by cytosolic Ca2+ concentration during secretion by this gland.