FIGURE 9.

Voltage dependence of block of T-338A-CFTR by internal ions depends on the transmembrane Cl⁻ gradient. (A) Example leak-subtracted I/V relationships recorded from inside out membrane patches. Currents were recorded before and after addition of 1 mM to the intracellular solution. Chloride concentration was reduced from 154 mM to 24 mM in either the intracellular (left) or extracellular (right) solution by partial replacement of NaCl by glucose. (B) Mean fractional current remaining (i/i₀) after addition of this concentration of to the intracellular solution, with symmetrical 154 mM Cl⁻ (•), 24 mM intracellular Cl⁻ (○), or 24 mM extracellular Cl⁻ (□). Mean of data from 4–6 patches.