Figure 3. Shift in Cl_ir activation induced by changes in pH_o.

A, cells were bathed in solutions with the pH adjusted to the indicated values. Control currents (pH_o = 7.4) are shown in the left-hand panel and test currents are shown in the right-hand panel (pH_o = 8.0). Membrane potential was changed from −120 to +40 mV in 20 mV steps. B, voltage dependency of channel activation at pH 7.4 (•, n = 5) and 8.0 (▴, n = 5). The analysis of these curves obtained from paired experiments was as described in Fig. 2B. The resulting average curves were fitted with the Boltzmann function to obtain the parameters V_0.5 and s displayed in the inset.