Fig 1. Whole-cell K⁺ currents in cultured PAECs.

(A) Representative whole-cell K⁺ currents were recorded in cultured PAECs. The whole cell currents were recorded with a holding potential at 0mV and command pulses from -100 mV to 100 mV. The recording was obtained under symmetrical conditions with bath and pipette solution containing 145mM K⁺. (B) Current traces obtained with a voltage-ramp command from -100mV to 100 mV and the reverse potential was near to 0 mV under symmetrical condition with bath and pipette solutions indicated in (A). (C) Current-voltage relationships were obtained from symmetrical condition indicated in (A) and replacing bath solution for 10 mM K⁺. The inwardly rectifying component was obviously reduced if the extracellular K⁺ concentration is decreased from 145 to 10 mM, and the reversal potential was shifted to –66 ± 1 mV. (D) Exposure of the cells to Ba²⁺ led to a strong inhibition of these K⁺ currents in the inward direction with very little effect on the outward currents.