title: Metal accumulation and antioxidant defenses in the freshwater fish Carassius auratus in response to single and combined exposure to cadmium and hydroxylated multi-walled carbon nanotubes.
abstract: The effects of cadmium, hydroxylated multi-walled carbon nanotubes, and their mixture on metal accumulation and antioxidant defenses were studied using the goldfish Carassius auratus as the test organism. The fish were exposed to 0.1 mg/L Cd, 0.5 mg/L OH-MWCNTs, or 0.1 mg/L Cd+0.5 mg/L OH-MWCNTs for 3 and 12 days. Then, the Cd concentration was determined in the gill, liver and muscle. Moreover, hepatic antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), glutathione level and malondialdehyde content were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation in tissues occurred in the following order: gill>liver>muscle at 3 days and liver>gill>muscle at 12 days. The concentrations of Cd in the livers of fish exposed to the combination of Cd+OH-MWCNTs were significantly higher than those in fish exposed to either single chemical after 12 d of exposure. Meanwhile, the mixture evoked severe oxidative stress in the exposed fish, as indicated by significant inhibition of SOD, CAT and GPx activity, a remarkable decrease in GSH level, and simultaneous elevation of MDA content. These results suggested that the effect of the combined factors on metal accumulation and oxidative stress biomarkers was more obvious than that of single factors at longer exposure durations.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China.
authors.forename: Ruijuan
authors.initials: R
authors.lastname: Qu
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China.
authors.forename: Xinghao
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China. Electronic address: wangzun315cn@163.com.
authors.forename: Zunyao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China.
authors.forename: Zhongbo
authors.initials: Z
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, PR China.
authors.forename: Liansheng
authors.initials: L
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000818:Animals; D002104:Cadmium / Q000737:chemistry / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D005880:Gills / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006054:Goldfish / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D002104:Cadmium; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione
keywords: Cadmium; Hydroxylated multi-walled carbon nanotubes; Metal accumulation; Oxidative stress biomarkers