Fig. 3. BK decreases the basolateral K⁺ conductance of the DCT and depolarizes the membrane.

A whole-cell recording shows Ba²⁺ -sensitive K⁺ currents in the DCT treated with 10 μM BK and the K⁺ currents were measured with a step protocol from −60 to 60 mV at a 20 mV step (A) or with Ramp protocol from −100 to 100 mV (B). Symmetrical 140 mmol/L KCl solution in the bath and pipette was used for the measurement. Results of six experiments are summarized in a bar graph (C). A whole-cell recording shows the effect of 10 μM BK on K⁺-current (I_K) reversal potential of the DCT (D). The bath solution contains (in mmol/L) 140 NaCl and 5 KCl while the pipette solution has 140 KCl. Results of five experiments are summarized in a bar graph (left panel of Fig. 3C).