Figure 8.

Increasing HCO₃⁻ concentration increases amiloride-sensitive current. [HCO₃⁻] was varied on the basolateral side (A, n = 4 for each condition) or on the apical side (B, n = 7 for each condition) of mpkCCD monolayers over 24 hours, by substituting HCO₃⁻ for methanesulfonate, whereas Na⁺ and Cl⁻ concentrations were held constant on both sides of the cell ([Na⁺] = 165 mM; [Cl⁻], 120 mM). (C) Effect of varying apical HCO₃⁻ concentration by substitution with Cl⁻. At each HCO₃⁻ concentration tested, current was unchanged with acetazolamide (200 μM) present on both sides of the cell. P < 0.05, ANOVA.