| Organotin compounds are widely used in industrial and agricultural production,which are difficult to be degraded in the environment.They can directly or indirectly cause poisoning,and can also be enriched in food of animal origin through biology,causing different degrees of harmness to animals and human health.Trimethyltin chloride(TMT)is an organic tin compound common in the production of plastics.It has high lipid solubility and water solubility.It can enter the body through the respiratory tract,digestive tract and skin mucosa,causing damages to various organs of the body.Animals feed ingredients come from a wide range of sources and are easily polluted by environmental toxicants.Therefore,in this paper,chickens and in vitro cultured hepatic LMH cells were taken as the research objects to preliminary explore the oxidative damage of chickens and LMH cells after exposure to trimethyltin chloride,which can give basis for the toxicity of TMT.In this study,2-day-old chickens were treated with TMT at doses of 2,4 and 8mg/kg.The clinical symptoms and pathological changes,serum biochemical indexes,liver function-related enzyme activities and apoptosis related genes were observed after TMT exposure.Results showed that chickens in the TMT exposure group showed clinical symptoms such as convulsions,mental fatigue,loss of appetite and squatting,and all died in the 8mg/kg group.The liver showed different degrees of degeneration and necrosis under microscope,especially the focal necrosis and diffuse cell necrosis in the liver of the 4 and8mg/kg exposure groups respectively.Results of serum biochemical examination showed that serum albumin,globulin,total protein,aspartate aminotransferase,amylase and creatine kinase increased in a dose-dependent way.The serum alanine aminotransferase activity,total bilirubin,triglyceride and inorganic phosphorus contents in 8mg/kg exposed group were significantly increased,while the creatinine and glucose contents were significantly decreased.At the same time,the contents of GSH in liver,brain tissue and serum of chicks decreased,while the contents of AST and ALT increased.The m RNA relative expressions of apoptosis-related genes Bax,Caspase-3,Caspase-8 and Caspase-9 in liver were significantly increased by q PCR assay,in which 2mg/kg and 4mg/kg TMT were dose-dependent upregulated.The results showed that TMT could induce oxidative damage and cell necrosis in chick liver,and induce apoptosis of liver cells at the same time.LMH cells were inoculated with 0.5,1,5 and 10 g/m L TMT to observe the effects of TMT on the oxidative indices,cell cycle and apoptosis of LMH cells.The results showed that the cell viability of LMH cells infected with different concentrations of TMT decreased by CCK8 assay after 12 hours,and the decrease was most significant in the 10 g/ ml TMT group.Microscopic observation showed that after TMT exposure,the cell morphology became slender,and in the 5 g/m L TMT group,a large number of cells became round and floated in the liquid in the 10 g/m L TMT group.The results of oxidative damage index showed that TMT reduced the contents of GSH and SOD,and increased the contents of MDA,AST and ALT in LMH cells.Flow cytometry results showed that LMH cells developed from G1 phase to S phase and were inhibited in G2/M phase after TMT exposure,leading to the termination of cell cycle and a significant increase in the rate of cell apoptosis at late stage.The changes of apoptosis-related genes detected by q PCR showed that the m RNA relative expressions of Caspase-3,Caspase-8,Bax and Bcl-2 in LMH cells were up-regulated after TMT exposure.The results showed that TMT could induce oxidative damage,inhibit proliferation and induce apoptosis of LMH cells in vitro. |
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