Biochemical responses of earthworm Eisenia fetida exposed to cadmium-contaminated soil with long duration.
The biochemical responses of the earthworms, Eisenia fetida, exposed to a series of Cd concentrations (0.00, 1.25, 2.50, 5.00 and 10.00 mg Cd(2+) kg(-1) soil) for up to 8 weeks were investigated, aiming to evaluate the sublethal effects of Cd with long exposure and to explore the potential for applying these responses as biomarkers to indicate the Cd-contaminated soil. The following biochemical parameters were determined: cytochrome P450 (CYP) contents and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-s-transferase (GST). Cadmium concentrations in all earthworms were apparently accumulated in 4 weeks, and showed minor changes in weeks 6-8 compared to the first 4 weeks. CYP presented a significant elevation in 2-4 weeks and a decline in 6-8 weeks in each treated group. The activities of SOD and CAT showed an obvious increase with exposure of 6-8 weeks while their levels were not affected in 4 weeks in each treated group. GST activity revealed significant activation starting from week 4. This study confirmed the significance of applying a suite of biomarkers rather than a selective choice to assess the impact of pollutants on organisms. It also indicated that the observed effects were more dependent upon exposure duration than dose.
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Shenyang 110016, People's Republic of China.
Xiaoxia
X
Yang
Yufang
Y
Song
M Leigh
ML
Ackland
Yang
Y
Liu
Xiufeng
X
Cao
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005982:Glutathione Transferase / Q000378:metabolism; D009835:Oligochaeta; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism
D015415:Biomarkers; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D002374:Catalase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase