RESUMO
AIM: To study the effects of sodium metabisulfite (SMB), sulfur dioxide (SO_2) and its derivatives in vivo, sodium bisulfite and sulfite, on Na~+ currents. The effects of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) against SMB were also studied in freshly dissociated hippocampal CA1 neurons in rats. METHODS: The whole-cell patch-clamp techniques were used in the experiments. RESULTS: ① SMB increased the voltage-activated Na~+ currents in a concentration-and voltage-dependent manner. The amplitudes of Na~+ currents was increased (22.36?3.28) % and (65.05?5.75)% (n=10) by SMB at 2 ?mol/L and 20 ?mol/L, respectively. ② SMB (10 ?mol/L) did not affect the activation process, but changed the inactivation process significantly. Before and after application of 10 ?mol/L SMB, the half-inactivation voltage was (-82.38)?0.54) mV and (-69.39)?0.41) mV (n=10, P