Fig. 4.

SLC4A11 does not exhibit current changes during Na⁺ dependent or independent H⁺/OH⁻/HCO₃⁻ changes in oocytes. SLC4A11 cRNA-injected or native oocytes were incubated for 72 h. pH and current were simultaneously measured with a double-barreled microelectrode combined with a two-electrode voltage clamp (clamped to −40 mV). A and B: current was measured when the native or SLC4A11-expressing oocytes, and were exposed to oocyte Ringer's solution (OR 7.4, white bar), OR containing only 10% Na⁺, adjusted to pH of 6.4 (10% Na⁺ 6.4, black bar), OR containing bicarbonate (HCO₃⁻ 7.4, gray bar), and OR containing only 10% Na⁺ and HCO₃⁻, adjusted to pH of 6.4 (10% Na⁺ HCO₃⁻ 6.4, black bar). Arrows across the top bar indicate the time period when rates of [H⁺]_i were measured, and the corresponding letters indicate the panel with the rates compared. C: membrane current mediated by SLC4A11 was calculated when oocytes were switched from OR 7.4 to 10% Na⁺, pH 6.4. D and E: membrane current mediated by SLC4A11 was calculated when oocytes were switched from OR 7.4 to HCO₃⁻ 7.4 and then to 10% Na⁺ and HCO₃⁻, pH 6.4. Error bars represent means ± SE (n = 7).