Response of antioxidant systems to copper in the gills of the clam Ruditapes decussatus

• Published in: Marine environmental research 2002-09, Vol.54 (3-5), p.413-417
• Main Authors: Geret, Florence, Serafim, Angela, Barreira, Luisa, João Bebianno, Maria
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Antioxidant enzymes; Applied ecology; Biological and medical sciences; Bivalvia - physiology; Catalase; Catalase - biosynthesis; Catalase - pharmacology; Clam; Copper; Copper - adverse effects; Dose-Response Relationship, Drug; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Environmental Exposure; Enzyme Induction; Fundamental and applied biological sciences. Psychology; Gills - physiology; Glutathion peroxidase; Glutathione Peroxidase - biosynthesis; Glutathione Peroxidase - pharmacology; Lipid Peroxidation; Malondialdehyde - analysis; Malondialdehyde - pharmacology; Marine; Metallothionein; Metallothionein - biosynthesis; Metallothionein - pharmacology; Ruditapes decussatus; Superoxide dismutase; Superoxide Dismutase - biosynthesis; Superoxide Dismutase - pharmacology
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/S0141-1136(02)00164-2

Copper (Cu) is an essential element for biological systems, however, when present in excess, is toxic. Metallothioneins can play an important role in Cu homeostasis and detoxification. Moreover, Cu can catalyse the production of toxic hydroxyl radicals that cause lipid peroxidation but defence systems in the cells can limit the oxidative damage. The present study was performed to investigate the effect of three Cu concentrations (0.5, 2.5 and 25 μg l−1) on the response of antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathion peroxidase and total glutathion peroxidase), total proteins, metallothioneins (MT), malondialdehyde (MDA) concentrations in the gills of the clam, Ruditapes decussatus. The activity of antioxidant enzymes and total proteins, MT and MDA concentrations were measured in the gills of the clams after 1, 3, 7, 14, 21 and 28 days of Cu exposure. Results indicate that Cu only induces an imbalance in the oxygen metabolism during the first week of Cu exposure due to a decrease in mitochondrial SOD and CAT, selenium-dependent and total glutathion peroxidase activities. Cu also causes lipid peroxidation, measured by the MDA formation, that was Cu dependent. In the gills of clams exposed to 25 μg Cu/l, the excess of Cu triggers the induction of MT synthesis after 3 days of exposure.