[Effect of SO2 derivatives on sodium currents in acutely isolated rat hippocampal CA1 neurons]

The effect of SO2 derivatives on Na(+) currents was studied in freshly dissociated hippocampal CA1 neurons of rat using the whole-cell patch-clamp technique. The results indicated that SO2 derivatives caused a dose-dependent and voltage-dependent increase in the voltage-activated Na+ currents. The amplitudes of Na(+) currents were increased by 50.59 19.08% and 82.06 18.51% (n=15)by SO2 derivatives at 10 and 100 micromol/L, respectively. The action was frequency-independent. The results also showed that SO2 derivatives did not affect the activation process, but changed the inactivation process significantly. Before and after application of 10 micromol/L SO2 derivatives, the half-inactivation voltage was -69.71+/-4.67 and -53.27+/-4.95 mV (n=10, P<0.01), respectively, but the slope factor was not changed. These results imply that SO2 derivatives have neurotoxic effects and that SO2 pollution is probably related to some diseases of central neuronal system.