Fig. 2.

Cl⁻, not H⁺, carries DIDS-sensitive current. Interpolated values of reversal potential (E_rev) of DIDS-sensitive current (measured as described in Fig.1B) listed next to Cl⁻ and H⁺ equilibrium potential values (E_Cl andE_H, respectively) set by bath and pipette solution compositions. Ruptured-patch recording mode was used. The control bath solution contained 53 mmCl⁻, the bath Cl⁻ was reduced to 11 mm by isosmotic replacement with DGA. The pipette solution contained 11 mm Cl⁻ and 30 nm free Zn²⁺ (see Materials and Methods for other constituents). Filled circles and error bars plot the mean ± 1 SEM of E_rev measured from the indicated number of cells. E_rev of DIDS-sensitive current shifts with E_Cl but not with E_H.