Inhibition of Ca2+-activated K+ channels in pig pancreatic acinar cells by Ba2+, Ca2+, quinine and quinidine

摘要: Abstract Patch-clamp whole-cell and single-channel current recordings were made from pig pancreatic acinar cells to test the effects of quinine, quinidine, Ba 2+ Ca . Voltage-clamp single isolated showed that high external concentrations or (88 mM) abolished outwad K + currents normally associated with depolarizing voltage steps. Lower only had small inhibitory whereas 11 mM almost blocked current. 5.5 reduced outward less than 30% control value. Both quinine quinidine (200–500 μM) markedly currents. In studies it was shown (1–5 probability opening high-conductance voltage-activated channels internal (6 · 10 −6 3 −5 M) caused activation at negative membrane potentials inhibition positive potentials. Quinidine (200–400 evoked rapid chopping channel openings acting both outside inside in this way total passing through channels.