DNA damage in brain of mice exposed to arsenic trioxide

[Objective] To provide evidences for exploring the mechanism of arsenic(As) toxicity to central nervous system.[Methods] Forty mice were divided into 4 groups,e.g.,one control and 3 experimental groups(1ppm As2O3,2 ppm As2O3,4 ppm As2O3).As2O3 was administered ad libitum in water for 60 days.Immunohistochemistry method was used to observe 8-hydroxy-2'-desoxyguanosine(8-OH-dG) expression in brain neurons of mice.Single cell gel electrophoresis method was used to examine the DNA breakage levels in these neurons of mice.[Results] The degenerative and necrotic pathological changes and stronger expression of 8-OH-dG were observed in the brain cortex of mice exposed to As.There were obvious comet tails in brain neurons of mice exposed to As,and the comet tail distances were increasing as the concentration of As increasing.[Conclusion] DNA damage of cortex neurons in mice was induced by arsenic in low dose,and cortex neurons mightbe main target of the arsenic neurotoxicity.