Ecotoxicology and Environmental Safety, April 1, 2012, Vol.78, p.296(14)
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ecoenv.2011.11.037 Byline: Vanessa Burmester (a), Jorge Nimptsch (b), Claudia Wiegand (c) Keywords: Glutathione S-transferase; Superoxide dismutase; Catalase; Microcystins; Dreissena polymorpha; Unio tumidus Abstract: Freshwater mussels such as the invasive Dreissena polymorpha and the indigenous Unio tumidus nourish by high filtration rates and may accumulate cyanobacteria and their toxins during cyanobacterial blooms. Physiological adaptations to cyanotoxins enable organisms to endure cyanobacterial blooms but may differ between species. Biotransformation and excretion capacities for cyanobacteria and anthropogenic pollutants have been demonstrated for Dreissena polymorpha but less for unionid species. This study compares the activities of biotransformation (glutathione S-transferase, GST) and antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT) in Dreissena polymorpha to Unio tumidus in response to cyanotoxin exposure (10[mu]gL.sup.-1 and 50[mu]gL.sup.-1 microcystin-LR, respectively, total microcystin from a cyanobacterial crude extract) for 24h and 7d exposure duration. Enzyme activities in Dreissena polymorpha were measured in the whole mussel tissue, digestive gland and in gills and in Unio tumidus in the digestive gland, gills, mantle, foot as well as in the remaining tissue. The sGST was elevated for the entire exposure period in the whole mussel tissue of Dreissena polymorpha but despite higher basal activities in digestive gland and gills of Unio tumidus, it was rather inhibited or unaltered in most of their tissues. Elevated SOD activity indicated oxidative stress response in Dreissena polymorpha, but not in Unio tumidus. The CAT activity was barely affected in both species, rather inhibited in Unio tumidus, despite again higher basal activities in digestive gland and remaining tissue. Compared to the indigenous Unio tumidus, the investigated biotransformation and oxidative stress combating enzymes respond stronger in the invasive Dreissena polymorpha. Author Affiliation: (a) Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Dept. Ecophysiology and Aquaculture, Muggelseedamm 301, 12587 Berlin, Germany (b) Universidad Austral de Chile, Instituto de Ciencias Marinas and Limnologicas, Las Encinas 220, Valdivia, Chile (c) University of Southern Denmark, Institute of Biology, Campusvej 55, 5230 Odense M, Denmark Article History: Received 26 July 2011; Revised 25 November 2011; Accepted 26 November 2011
Superoxides -- Physiological Aspects ; Thiols -- Physiological Aspects ; Enzymes -- Physiological Aspects ; Antioxidants (Nutrients) -- Physiological Aspects ; Glutathione Transferase -- Physiological Aspects ; Enzymology -- Physiological Aspects ; Mussels -- Physiological Aspects ; Marine Toxins -- Physiological Aspects
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