Figure 5.

The effects of ZnCl₂ are strongly dependent on pH_o. Families of voltage-clamp currents are shown at pH_o 7.0, 6.0, and 5.0, with pH_i 5.5, recorded in the absence (left-most family in each row) and presence of the indicated concentration of ZnCl₂. Data in each row are from the same cell, were recorded during an identical family of voltage pulses, and the same calibration bars apply. The cell at pH_o 7.0 was held at −60 mV, and pulses were applied from −40 to +20 mV in 10-mV increments. The cell at pH_o 6.0 was held at −20 mV and pulses applied from +10 to +70 mV in 10-mV increments. The cell at pH_o 5.0 was held at −20 mV and pulses applied from +50 to +100 mV in 10-mV increments.