DTT and cadmium alter levels of A43C currents. Macroscopic currents elicited from an oocyte expressing A43C unapposed hemichannels with the voltage paradigm shown at the top of the panel. The central bar indicates the time and duration at which the bath solution containing 100 mM Cs-MES, 1.8 mM CaCl₂, and 10 mM HEPES, pH 7.6, was exchanged with the same bath solution except containing either 20 µM DTT or 10 µM CdCl₂. Currents increased to a steady-state level approximately fivefold greater than the initial currents after exposure to 20 µM DTT and decreased to ∼80% of maximum after treatment with 10 µM CdCl₂. The reduction in current was not changed substantially by washing with the bath solution but was reversed to pre-cadmium levels after wash with 20 µM DTT.