纳米二氧化钛经口暴露对小鼠肝脏的影响

目的 探讨纳米二氧化钛(TiO2 NPs)经口暴露后对小鼠肝脏的影响。方法 60只健康雄性ICR小鼠随机分为对照组、TiO2 NPs (10、50、100) mg/kg·BW染毒组，连续灌胃30 d后，颈椎脱臼处死小鼠，计算小鼠肝脏系数，观察小鼠肝脏组织病理学切片，测定肝组织匀浆中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)，超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH - PX)、总抗氧化能力(T - AOC)活力以及丙二醛(MDA)含量。结果 与对照组相比，各染毒组小鼠肝脏系数差异无统计学意义(P＞0.05)；病理学切片观察各染毒组肝脏组织均可见不同程度肝组织损伤；随着TiO2 NPs染毒剂量的增加，ALT、AST活力以及MDA含量在50、100 mg/kg·BW组升高，SOD活性在100 mg/kg·BW组降低，GSH - PX活性在50、100 mg/kg·BW组降低，T - AOC水平在10、50、100 mg/kg·BW组均降低，差异均具有统计学意义(P＜0.05)。结论 经口暴露TiO2 NPs，可使小鼠肝脏发生氧化应激反应，造成肝脏氧化损伤，并最终导致小鼠肝脏组织结构及功能破坏，具有一定的肝脏毒性作用。

Effect of liver after oral exposure to titanium dioxide nanoparticles in mice

Objective The research was performed to explore the effect of titanium dioxide nanoparticles(TiO2 NPs) on liver after oral exposure to in mice. Methods 60 healthy male ICR mice were randomly divided into control group and TiO2 NPs(10,50,100) mg/kg·BW groups. The mice were exposed to TiO2 NPs via intragastric administration for 30 days.The liver coefficient, liver histopathology, alanine aminotransferase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC) activity and malondialdehyde (MDA) content were assessed after the mice were killed. Results The difference was not statistically significant of liver coefficient among TiO2 NPs exposed groups compared with that of control group(P>0.05). Histopathological sections were observed that the liver tissue damage in varying degrees in all TiO2 NPs exposed groups.With the increase of the dose of TiO2 NPs, the levels of ALT, AST and MDA showed increased in the 50 and 100 mg/kg·BW groups, SOD activity showed decreased in the 100 mg/kg·BW group, GSH-PX activity showed decreased in the 50 and 100 mg/kg·BW groups, T-AOC level showed decreased in 10,50,100 mg/kg BW groups, the difference was statistically significant(P<0.05). Conclusion Oral exposure to TiO2 NPs can cause liver tissue structure and function destruction, oxidative stress may be implicated in TiO2 NPs induced liver toxicity.