Figure 9. Comparing the effects on pH_i of Ba²⁺ extrusion with those of H⁺ injection.

The preparation was bathed in Ca²⁺-free (Ba²⁺) saline throughout. After depolarizations to −10, −20 and −10 mV for 5, 5 and 10 s, respectively, an HCl-filled microelectrode was inserted and used to make 3 injections of H⁺. Finally the depolarization to −10 mV for 5 s was repeated twice.