Abstract: BACKGROUND AND AIM: To explore the effects of transbronchial TiO2 nanoparticles(size 50 nm) poisoning on liver and kidney in rats. MATERIALS AND METHODS: 24 SD rats were randomly divided into 0.5, 5.0 and 50.0 mg/kg nano-TiO2 groups and control group(0.15％ sodium chloride solution). Rats were treated with intratracheal TiO2 nanoparticle suspension and were sacrificed after 7 days. Complete blood count and biochemical indexes and tissue coefficients were assessed. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) and the contents of maleic dialdehyde (MDA) in plasma, liver and kidney were measured. Pathological changes of liver and kidney were also examined. RESULTS: Indexes of blood count, blood biochemistry and tissue coefficients did not show statistical significance between nano_TiO2 exposure groups and control group. Kidney SOD activities of 5.0 and 50.0 mg/kg nano_TiO2 groups were obviously decreased compared with that in control group(P<0.05). GSH-PX activities in plasma and kidney of 50.0 mg/kg nano-TiO2 group were lower than that in control group(P<0.05). In liver, MDA contents of 0.5 and 5.0 mg/kg nano-TiO2 groups were significantly increased compared to the control group (P<0.05). No obvious pathological changes of liver and kidney was observed. CONCLUSION: Acute transbronchial exposure to TiO2 nanopaticles could induce oxidative stress in the liver and kidney, but did not influence hepatic or renal functions nor cause pathological changes . Its biological and toxicological significance needs further studies.

Key words: titanium dioxide nanoparticles, liver, kidney, oxidative stress