The Co-induced Effects Of Molybdenum And Cadmium On The Antioxidant Function Of Liver Mitochondrial And The MRNA Expression Levels Of Related Apoptosis Genes In Duck Livers

To investigate the toxicology relationship between Molybdenum(Mo) and Cadmium(Cd), the co-induced effects of Mo and Cd on antioxidant function of liver mitochondria, ultrastructure of liver tissue, m RNA expression levels of related apoptosis genes were determined in this study. Hexaammonium molybdate((NH4)6Mo7O24·4H2O) and cadmium sulfate and 8/3-hydrate(3Cd SO4·8H2O) were used as sources of Mo and Cd. 360 11-day-old healthy ducks were divided into six groups randomly(30 male, 30 female). Mo and Cd were added into basal diet based on diet weight, the dosage of each group were: control group(Mo 0mg, Cd 0mg),low Mo group(Mo 15 mg, Cd 0mg), high Mo group(Mo 100 mg, Cd 0mg), Cd group(Mo 0mg, Cd 4mg), low Mo+Cd group(Mo 15 mg, Cd 4mg), high Mo+Cd group(Mo 100 mg, Cd 4mg). The time span for experiment was 120 days, 10 ducks(5 male, 5 female) of each group were selected to collect samples on days 30, 60, 90 and 120 respectively for determining the T-AOC, MDA content and activities of CAT, NOS,SOD and XOD in liver mitochondria, contents of TG、HDL-c、LDL-c、DBIL、IBIL、CP in serum, m RNA expression levels of apoptosis genes: Bcl-2、Bak-1 and Caspase-3. In addition, ultrastructural changes of hepatocytes were also observed. The results are shown as followings:1. Except the low Mo group, the activities of CAT and SOD in liver mitochondria decreased significantly(P<0.05) in experimental groups as compared to control groups during all the experiment time while the T-AOC and XOD activity decreased significantly(P<0.05) at 60, 90 and 120 days. What’s more,there was significant difference(P<0.05) between combination groups and single treated with Mo or Cd groups. The MDA content and NOS activity in liver mitochondria increased significantly(P<0.05) compared to control groups with significant difference(P<0.05) between combination groups and single treated with Mo or Cd groups.2. Except the low Mo group, contents of TG, LDL-c, DBIL, IBIL in serum increasedsignificantly(P<0.05) in experimental groups than that in the control groups. Meanwhile,they were significant higher(P<0.05) in combination groups than that in single treated groups. Contents of HDL-c, CP in serum decreased significantly(P<0.05) in experimental groups and they were significant lower(P<0.05) in combination groups.3. Except the low Mo group, the m RNA expression levels of Bak-1 and Caspase-3 increased while Bcl-2 decreased significantly(P<0.05) in experimental groups as compared to control groups with significant difference(P<0.05) between combination groups and single treated with Mo or Cd groups.4. Ultrastructural changes of hepatocyte showed karyopyknosis of hepatocyte, karyopyknosis, swelling, vacuolation, crest broke of mitochondria in Cd group, HMo and HMo+Cd groups on 120 day.Conclusion: Co-induction of Mo and Cd as well as single Mo or Cd could cause damage to antioxidant function of liver mitochondria, pathological changes such as karyopyknosis of hepatocyte, swelling, vacuolation, crest broke of mitochondria. Additionly, m RNA expression levels of Bak-1 and capase-3 were upregulated while Bcl-2 level decreased. Mo and Cd may have synergistic effect on hepatotoxicity in ducks.