Multi-biomarker responses in the freshwater mussel Dreissena polymorpha exposed to polychlorobiphenyls and metals.
Contaminant related changes in behavioral, phase I and II metabolizing enzymes and pro-oxidant/antioxidant processes in the freshwater mussels Dreissena polymorpha exposed to metals and PCBs were assessed. Behavioral and biochemical responses including filtering rates, key phase I, II and antioxidant enzymes and levels of metallothioneins, glutathione, lipid peroxidation and DNA strand breaks were determined in digestive glands of mussels after being exposed to sublethal levels of mercury chloride, methyl mercury, cadmium and Aroclor 1260 during 5 days. In 7 out of 12 responses analyzed, mussels showed significant differences across treatments. Unusual properties of measured ethoxyresorufin-O-deethylase (EROD) activities indicated that mussels lack an inducible CYP1A enzymatic activity. Despite of using similar exposure levels, inorganic and organic mercury showed different biomarker patterns of response with methyl mercury being more bio-available and unable to induce metallothionein proteins. Mussels exposed to Cd presented higher levels of metallothioneins and an enhanced metabolism of glutathione, whereas those exposed to Aroclor showed their antioxidant glutathione peroxidase related enzyme activities inhibited. Although there was evidence for increased lipid peroxidation under exposure to inorganic and organic mercury, only mussels exposed to Aroclor had significant greater levels than those in controls.
Faria
Melissa
M
Laboratory of Environmental Toxicology (UPC), CN 150 Km 14.5, Terrassa 08220, Spain.
Carrasco
Luis
L
Diez
Sergi
S
Riva
Maria Carmen
MC
Bayona
Josep Maria
JM
Barata
Carlos
C
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001140:Aroclors / Q000633:toxicity*; D015415:Biomarkers / Q000378:metabolism*; D019256:Cadmium Chloride / Q000633:toxicity; D053960:DNA Breaks; D049875:Dreissena / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D004798:Enzymes / Q000378:metabolism; D005618:Fresh Water; D015227:Lipid Peroxidation / Q000187:drug effects; D008627:Mercuric Chloride / Q000633:toxicity; D008668:Metallothionein / Q000378:metabolism; D008670:Metals / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D000975:Antioxidants; D001140:Aroclors; D015415:Biomarkers; D004798:Enzymes; D008670:Metals; D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; C026987:aroclor 1260; D008627:Mercuric Chloride; D008668:Metallothionein; D019256:Cadmium Chloride