Voltage-dependence of average attenuation and 9-ACA-sensitive I_Cl’s at various [Cl]_i. (A–C) Graphs show the voltage dependence of the maximal attenuation obtained from fibers equilibrated with 70 mM (V_H = −20 mV, n = 8); 40 mM (V_H = −40 mV, n = 4), and 10 mM (V_H = −70 mV, n = 3) [Cl]_i, respectively. The maximal peak attenuation (at −140 mV) was 27.4 ± 1.8% and 18.5 ± 3.5% for 70 and 40 mM [Cl]_I, respectively. Statistical significance with respect to peak attenuation values at −140 mV is denoted by *. Statistical significance with respect to values at −120 mV is denoted by #. The symbol o indicates significance with respect to all data at negative voltages. D–F are the corresponding plots of the peak 9-ACA–sensitive I_Cl obtained from the same fibers as in A–C, respectively. The error bars represent SEM. V_H values are indicated by the arrows.