Fig. 3.

Effect of increasing [K⁺]_o on ROMK currents in the rat CCD. A: whole-cell recording showing outward currents at a holding potential of 0 mV. Whole-cell clamps were formed in the presence of 1 mM [K⁺]_o. Currents declined with 1 mM [K⁺]_o but stabilized in the presence of 10 mM [K⁺]_o. At the end of the recording, TPNQ (100 nM) was added to the medium to measure the ROMK-specific currents. B: summary of 5 similar pairs of experiments. Data represent means ± SE. *P < 0.05, significant difference.