RESUMO
Aim To investigate the effects of K + channel blockers on arsenic trioxide-induced HeLa cell death. Methods Viability of HeLa cells was assessed by mitochondrial dehydrogenase activity using colorimetric MTT assay and the voltage-dependent K+ currents were recorded by using patch-clamp rest living cells after As2 O3 24 h-incubation showed significant increase of K + currents densities. At + 80mV, the densities of K+ currents (61 ± 18) pA/10 pF (n = 8) in As2O3 24 h-incubation group were significantly more than that in the control group (38 ± 10) pA/10 pF (n = 8, P ＜ 0. 05 ). The HeLa cells were prevented partially from As2 O3-induced cell death by co-application for 24 h with typical voltageeffects on HeLa cells. Conclusion Chronic treatment with As2 O3 increased voltage-dependent K+currents in HeLa cells and the cell death induced by As2O3 was reduced partially by voltage-dependent K +channel blockers, 4-aminopyridine or tetraethylammonium.