Proteasome and antioxidant responses in Cottus gobio during a combined exposure to heat stress and cadmium.
Temperature and trace metals are common environmental stressors, and their importance is increasing due to global climate change and anthropogenic pollution. Oxidative damage and antioxidant properties have been studied in liver and gills of the European bullhead (Cottus gobio) subjected to cadmium (CdCl(2) at nominal concentrations of 0.01 and 1mg/L) for 4 days at either 15°C or 21°C. First, exposure to 1mg Cd/L induced a high mortality rate (67%) in fish held at 21°C. Regarding the antioxidant enzymes, exposure to 0.01 mg Cd/L significantly increased the activity of superoxide dismutase (SOD) and decreased the activity of glutathione reductase (GR) in liver, independently of heat stress. In gills, exposure to 21°C resulted in a significantly increased activity of glutathione peroxidase (GPx), whereas the activity of glutathione S-transferase (GST) was significantly reduced as compared to fish exposed to 15°C. Furthermore, regardless of Cd stress, exposure to elevated temperature resulted in a significant decrease of lipid peroxidation (LPO) level in liver and in a significant increase in the activity of chymotrypsin-like 20S proteasome in both studied tissues of C. gobio. Overall, the present results indicated that elevated temperature and cadmium exposure independently influenced the antioxidant defense system in bullhead with clear tissue-specific and stress-specific antioxidant responses. Further, elevated temperature affected the hepatic lipid peroxidation and the activity of 20S proteasome in both tissues.
Research Unit in Environmental and Evolutionary Biology (URBE), The University of Namur (FUNDP), Rue de Bruxelles 61, B-5000, Namur, Belgium. jennifer.dorts@fundp.ac.be
Jennifer
J
Dorts
Aurélie
A
Bauwin
Patrick
P
Kestemont
Sabrina
S
Jolly
Wilfried
W
Sanchez
Frédéric
F
Silvestre
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002104:Cadmium / Q000633:toxicity*; D002918:Chymotrypsin / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005399:Fishes / Q000378:metabolism*; D005880:Gills / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006358:Hot Temperature; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity
D000975:Antioxidants; D014874:Water Pollutants, Chemical; D002104:Cadmium; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D002918:Chymotrypsin; D046988:Proteasome Endopeptidase Complex