Effects Of Cadmium Stress And Cadmium/cerium Interaction Impact On Physiological Function Of Misgurnus Anguillicaudatus

Loach Misgurnus anguillicaudatus was exposed to Cd at 0.025, 0.25, 2.5mg/L and Cd supplied with Ce at 0.5mg/L. Poisonous effect of Cd and interactional impact of Cd/Ce on liver tissue of loach were investigate. The antioxidant enzyme activities and lipid peroxidation of liver tissue were maeasured after exposure of Cd and Cd/Ce. DNA damage of liver cell was examined by Single Cell Gel Assay (SCGE). Chang of component and structure for liver cell of loach was measurede by foruier transform infranred spectrum (FTIR) method. Following is result.1.The superoxide dismutase(SOD), catalase(CAT), peroxidase(POD), and malonyldialdehyde(MDA) of Misgurnus anguillicaudatus liver tissue were measured after treatment with Cd and Cd+Ce. Cd at concentration of less than 0.025mg/L slightly harms antioxidant enzyme activities and lipid peroxidation of Misgurnus anguillicaudatus liver tissue. Long time of exposure of Cd at concentration more than 0.25mg/L could significantly inhibit antioxidant enzyme activities and seriously harm lipid peroxidation of liver tissue. Supplement with 0.5mg/L Ce3+ can alleviate the lipid peroxidation damage when Cd level is form 0.025mg/L to 0.25mg/L. When Cd concertration is more than 2.5mg/L, Supplement with 0.5mg/L Ce3+ can provide limited alleviation.2. Liver cell DNA damage Misgurnus anguillicaudatus treated with Cd and Cd+Ce was measured by Single Cell Gel Assay. It indicates that the comet tail DNA percentage, tail length/comet head diameter, and comet tail moment with treatment at concentration form 0.025mg/L to 0.25mg/L significantly increased compared with the control group. TL/D of treatment with Cd of 3 concentrations is more than 0.6 and cell DNA damage of 3 Cd treatments is greater than level three. It is suggested that Cd stress seriously harms the DNA integrity and affects genetic stability of liver cell. It is supposed that there is a dosage dependent effect of Cd on DNA damage of Misgurnus anguillicaudatus liver cell. Supplement of 0.5mg/L Ce with Cd stress at level of 0.025 mg/L and 0.25mg/L could significantly reduce DNA damage of liver cell including comet tail DNA percentage and TL/D (both P<0.05). 0.25mg/L Cd supplied with 0.5mg/L Ce can significantly reduce comet tail moment compared with the 0.25mg/L Cd treatment(P<0.01), while supplement of 0.5mg/L Ce to 2.5mg/L Cd2+ can't significantly reduce it(P>0.05).3. Impact on liver tissue of Misgurnus anguillicaudatus by Cd and Cd+Ce was measured by foruier transform infranred spectrum. It indicates that Cd at 0.025 mg/L and 0.25mg/L could change nucleic acid conformation and reduce the structural stability. 2.5mg/L Cd could destroy protein secondary structure and reduce spatial structure stability of membrane protein and injure function of membrane. Supplement with 0.5mg/L Ce to treatment of Cd at 0.025 mg/L and 0.25mg/L could reduce negative effect on ingredient, conformation and content of moleculars. When treatment concentration of Cd reaches 2.5mg/L,0.5mg/L Ce can collaborate to destroyed conformation of each groups and to reduced stability of nucleic acid and protein spatial structure.