Figure 10. Comparing the effects of Ba²⁺ extrusion and HCl injection on pH_i.

A, data from the experiment partially shown in Fig. 7. The pH_i changes following Ba²⁺ extrusion for 9 depolarizations (□) and 5 HCl injections (•) are plotted against the charge carried by the Ba²⁺ influx or the charge used to inject the H⁺. B, the average pH_i changes for H⁺ injection plotted against those caused by Ba²⁺ extrusion expressed per unit charge for 8 experiments. The average ratio between the pH_i changes induced by Ba²⁺ and H⁺ was 0.89.