The Study On Nickel Chloride-induced Pulmonary Oxidative Stress And Inflammatory Responses In Broilers

The purpose of this study was to observe different doses of nickel chloride(NiCl2)-caused pulmonary inflammatory responses and oxidative damage in broiler chickens.Two hundred and eighty avian broilers were randomly divided into four groups and fed on a control diet(corn-bean basal diet)or diets supplemented with 300,600 and 900 mg/kg nickel chloride(NiCl2)for 42 days.Samples were collected at 14,28 and 42 days during the experiment.By using methods of experimental pathology,ELISA and quantitative real-time polymerase chain reaction(qRT-PCR),we observed oxidative damage and inflammatory response parameter changes caused by dietary NiCl2 when compared with the control group.The results were as follows:1.In comparison to the control group,pulmonary organ index was reduced,and pulmonary development was inhibited in the NiCl2-treated groups.The alveolar epithelial cells were swollen,the alveolar walls were thickened with infiltration of inflammatory cells,and congestion and hemorrhage.The normal alveolar architecture was disordered or disappeared with alveolar epithelial cells,macrophages and lymphocyte.Also,necrotic cells and necrotic pulmonary were observed.2.In comparison to the control group,the contents of 8-OHdGS MDA and NO were significantly increased(P<0.05 or P<0.01),and activities of T-AOC,Cu-Zn SOD,Mn SOD,CAT,GSH-Px,GR,GST and ability to inhibit hydroxyl radical and GSH content,the ratio of GSH/GSSG were significantly decreased(P<0.05 or P<0.01),while the content of GSSG was significantly increased(P<0.05 or P<0.01)in the three NiCl2-treated groups.Also mRNA expression levels of CuZn-SOD,Mn-SOD,CAT,GSH-Px,GR,GST were significantly decreased(P<0.05 or P<0.01).3.Results from qRT-PCR showed that mRNA expression levels of iNOS,TNF-?,COX-2,IL-1?,IL-6,IL-8,IL-18 and IFN-y were higher via NF-?B activation,and mRNA expression levels of the anti-inflammatory mediators including IL-2,IL-4 and IL-13 were lower in the NiCl2-treated groups than those in the control group.Conclusion The above results showed that dietary NiCl2 in 300 mg/kg and over induces pulmonary oxidative damage and inflammatory responses,which then cuases pulmonary lesions and dysfunction.Alteration of mRNA expression of antioxidative enzymes and inflammatory factors is the melocular basis of dietary NiCl2-cuased pulmonary oxidative damage and inflammatory responses.