Duan S M, Zhang Y L, Wang Y
Department of Occupational and Environmental Health Sciences, Peking University of School of Public Health, Beijing 100191, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2018 Jun 18;50(3):395-400.
To compare the effects of different sized titanium dioxide (titanium dioxide, TiO) on the antioxidant function of liver tissues in mice, and study the effect of TiO nanoparticles on the susceptibility of lipopolysaccharide (LPS) on liver tissues.
Ninety 4-week-old clean-grade male ICR mice were divided into 18 groups, in which the mice were fed for different feed involving ordinary feed, nanometer TiO feed which meant the feed including 1% (mass fraction) TiO nanoparticles, and submicron TiO feed which meant the feed including 1% (mass fraction) TiO submicron particles. Respectively, they were fed for 1 month, 3 months and 6 months. On the second day after the feeding, respectively, 0 and 10 mg/kg LPS were given by gavage. The mice were harvested after 4 h and the body weight and liver weight for calculating the liver coefficient were recorded. Then the liver tissue homogenates were prepared for determining the antioxidant indexes including the total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA).
The change of body weight in mice was only discovered in group fed for 1 month, which showed significant decrease of body weight in treatment groups compared with control group. And there was no significant change of the liver coefficient in each group. Compared with control groups, nanometer TiO groups and submicron TiO group, the activity of T-AOC, T-SOD and MDA of nanometer TiO+LPS group and submicron TiO+LPS group in which the mice were fed for 1 month and 6 months increased in different degree. And another result was also existing. The MDA activity of liver in different sized treatment groups fed for 3 months decreased. Neither significant difference between the results of different sized TiO treatment groups, nor significant difference among different sized TiO groups and the control groups were observed.
Longterm peroral TiO nanoparticles and TiO submicron particles are more likely to cause damage to the liver in the growing mice, and the damage may be either reductive or oxidative. In addition, small sized TiO can increase the susceptibility of mice liver to LPS and the susceptibility will increase with the increase of exposure time.
比较不同粒径二氧化钛（TiO₂）对小鼠肝脏组织抗氧化功能的影响，研究TiO₂纳米颗粒对肝脏组织脂多糖（LPS）易感性的影响。
将90只4周龄清洁级雄性ICR小鼠分为18组，分别给予普通饲料、含1%（质量分数）TiO₂纳米颗粒的纳米TiO₂饲料、含1%（质量分数）TiO₂亚微米颗粒的亚微米TiO₂饲料喂养，分别喂养1个月、3个月和6个月。喂养后次日，分别经口给予0和10 mg/kg LPS。4 h后处死小鼠，记录体重和肝脏重量以计算肝脏系数。然后制备肝脏组织匀浆，测定总抗氧化能力（T-AOC）、总超氧化物歧化酶（T-SOD）、谷胱甘肽过氧化物酶（GSH-PX）和丙二醛（MDA）等抗氧化指标。
仅在喂养1个月的组中发现小鼠体重有变化，各处理组体重较对照组显著下降。各组肝脏系数无显著变化。与对照组、纳米TiO₂组和亚微米TiO₂组相比，喂养1个月和6个月的纳米TiO₂+LPS组和亚微米TiO₂+LPS组的T-AOC、T-SOD活性及MDA含量均有不同程度升高。还有一个结果是，喂养3个月的不同粒径处理组肝脏MDA活性降低。不同粒径TiO₂处理组之间以及不同粒径TiO₂组与对照组之间的结果均无显著差异。
长期经口给予TiO₂纳米颗粒和TiO₂亚微米颗粒更易对生长中小鼠的肝脏造成损害，这种损害可能是还原性的或氧化性的。此外，小粒径TiO₂可增加小鼠肝脏对LPS的易感性，且易感性随暴露时间的增加而增加。
