Modulation of sodium metabisulfite on L-type calcium current in rat dorsal root ganglion neurons
焦亚硫酸钠对大鼠背根节神经元L-型钙电流的影响

To explore the regulating role of SO2 and its derivatives on the physiological function of dorsal root ganglion (DRG) neurons, the effect of sodium metabisulfite (SMB), a common sulfur dioxide (SO2) derivative and food preservative, on the L-type calcium current (ICa,L) of rat DRG neurons was studied using the whole cell configuration by patch-clamp technique. The present results show that SMB increased the ICa,L in a concentration-and voltage-dependent manner. SMB shifted both the steady-state activation and the inactivation curves of ICa,L to more positive potentials, and the shift of the inactivation curves was more pronounced than that of the activation curves. The increase of ICa,L by SMB might cause an increase of intracellular calcium concentration via voltage-gated L-type calcium channels. These results lead to the conclusion that SO2 and its derivatives could regulate the physiological function of DRG neurons, and these chemicals at high concentrations could also cause pathophysiologic changes of the neurons.