Study On The Echanism Of Genotoxicity Induced By Indium Sulfate And Vc Rival Effect

Objective: Indium is a rare metal in the nature, which is widely used in recent years and become a very important material of modern electronic industry as the unique physical and chemical properties. The indium which is absorbed into the blood is rapidly transported to the soft tissue and the bone. The colloid indium is sent to the reticulo-endothelium system of the liver and spleen after it is swallowed by the leucocyte. The absorbed indium excrete from the body by the urine and dung. This period contains two parts. Fast discharge period needs twenty days and the excretion become slow then, which will go through several months or years. The soluble indium compound is poisonous. The indium sulfate is a representative of the soluble indium compound and it is also one of the main risk factors of professional to the workers engaged in the indium industry.The aim of the research is to examine the effect of indium sulfate on V79 cell DNA damage and chromosome viability in order to explore the mechanism of genotoxicity of indium sulfate. To assay the release of intracellular ROS and the change of mitochondrial membrane potential (Δψm), we discuss the the toxic mechanism and the rivalry of vitamin C in order to find the effective antagonist. It can provide the laboratory data for the prevention of the environmental exposure and the protection of exposed workers in the future.Methods: The research is mainly divided into three parts. First, the viability of V79 cells is measured by MTT method and the dose-effect relation could be decided. According to the result, we can make the dosage range of the indium sulfate for the rest of the experiment. Second, according to the dosage range of the indium sulfate, we observe the effect of indium sulfate on V79 cell DNA damage and chromosome viability. The DNA damage is examined by SCGE and the chromosome influence is tested by cytokinesis-block micronucleus (CBMN). Third, we discuss the influence of indium sulfate to the intracellular ROS and the mitochondrial membrane potential (Δψm) for explaining the toxic mechanism of indium sulfate on DNA and chromosome damage. When we mix vitamin C to the cell culture food, the rivalry of vitamin C is tested in order to find the effective antagonist.Results: As showed in the MTT assay, we could observe that V79 cell proliferation was inhibited by indium sulfate(treated 2hours, at the concentration of 0.5 mmol/L)and concentration–dependent relationship and time-dependent relationship were shown(P<0.05). Under the function of 1 mmol/L indium sulfate, the morphology change of V79 cell was observed. And when the concentration of indium sulfate goes up to 8 mmol/L, the cell apoptosis rate was increased obviously. In the further research, we found that indium sulfate can damage the cell DNA and chromosome. The damaged cell rate, tail length,Olive tail moment and tail DNA% of treated groups increased significantly with increasing of indium sulfate concentration.The rate of micronucleus in V79 cell was also increased as the increasing of indium sulfate. The intracellular ROS were raised while the mitochondrial membrane potential (Δψm) were reduced as the increasing of the indium sulfate concentration. The statistic difference was significant (P<0.05). And the vitamin C can rival the damage of DNA,we infer that the vitamin C could rival the ROS increasing andΔψm reducing.Conclusion: The indium sulfate can inhibit the V79 cell proliferation with low concentration in short time. The indium sulfate can increase the intracellular ROS and reduce the mitochondrial membrane potential (Δψm), damage the cell DNA and chromosome, then the cell apoptosis rate was increased. But the vitamin C can decrease the apoptosis rate in low concentration. The vitamin C can rival the ROS increasing andΔψm reducing induced by indium sulfate. From the above, it indicates that indium sulfate increase the ROS to damage the cell DNA,chromosome and the viability ofΔψm, so it shows an obvious genotoxicity.