Tea polyphenols inhibit the incremental effects of sulfur dioxide derivatives on sodium currents in cardiomyocytes / 中国病理生理杂志

ABSTRACT

AIM:To probe into the toxicological mechanism of sulfur dioxide (SO2) and its derivatives on cardiovascular system.METHODS: Effects of tea polyphenols (TP) on the increase in sodium current (INa) induced by SO2 derivatives in the cardiomyocytes were studied using the whole cell patch-clamp technique.RESULTS: ① The increase in INa induced by SO2 derivatives was inhibited by treating the cells with TP at different concentrations (10, 20 or 50 mg/L) in a dose dependent manner. At concentration of 50 mg/L, TP completely inhibited the increase in INa by SO2 derivatives. ② SO2 derivatives led to shift left of the activation curve. After application of TP at dose of 50 mg/L, the curve showed resumed significantly. ③ TP changed the inactivation process significantly. Before and after the application of SO2 derivatives, the half-inactivation voltage of INa was -(71.94?0.23) mV and -(65.79?0.69) mV (n=8, P0.05).CONCLUSION: TP inhibits the incremental effects of SO2 derivatives on INa, suggesting that the toxicity of SO2 on cardiomyocytes of rat is induced by free radical.