title: Effects of cadmium exposure on lipid peroxidation and the antioxidant system in fourth-instar larvae of Propsilocerus akamusi (Diptera: Chironomidae) under laboratory conditions.
abstract: Enzymatic antioxidants such as selenium-dependent glutathione peroxidase (GPx), glutathione transferase (GST), glutathione reductase (GR), and superoxide dismutases (SOD), as well as the concentration of hydrogen peroxide (H2O2) and malondialdehyde (MDA, an indicator of lipid peroxidation) were determined to identify which antioxidant enzymes participate in the efficient scavenging of ROS generated upon exposure to high doses of Cd2+ in fourth-instar Propsilocerus akamusi (Tokuna) (Diptera: Chironomidae) larvae after 72-h exposure. A significant increase in MDA levels and a change in GR and GPx activities in the Cd(2+)-treated P. akamusi were observed. The MDA in 25.0 and 50.0 mmol/liter treatments was significantly higher than that of the control dose after 72 h exposure. GPx activity was significantly induced by Cd2+ exposure only in the 50.0-mmol/liter treatment with a 0.59-fold increase in the control. All doses of Cd2+ significantly suppressed GR activity compared with the findings for the control dose, with an inhibited rate up to 0.55-fold in the 25.0 mmol/liter Cd2+ treatment. SOD and GST activities were not altered. The results indicate that Cd2+ can induce oxidative stress as indicated by the changes in lipid peroxidation and antioxidant status. For P. akamusi, an increase in the dose that the threshold needed for defense (namely, MDA level and GPx activity) activation was achieved. From this, organisms can be hypothesized to enable cells to avoid oxidant stress up to a certain extent where damage is again measurable (higher Cd2+ concentration).
authors: College of Life Science and Technology, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China.
authors: Xianyun
authors: X
authors: Zheng
authors: Wenmin
authors: W
authors: Long
authors: Yaping
authors: Y
authors: Guo
authors: Enbo
authors: E
authors: Ma
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002104:Cadmium / Q000633:toxicity*; D002683:Chironomidae / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis; D007814:Larva / Q000187:drug effects / Q000201:enzymology; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000032:analysis; D010088:Oxidoreductases / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002104:Cadmium; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D005982:Glutathione Transferase