title: Accumulation and toxicity of copper oxide nanoparticles in the digestive gland of Mytilus galloprovincialis.
abstract: Given the wide use of CuO nanoparticles in various industrial and commercial applications they will inevitably end up in the aquatic environment. However, little information exists on their biological effects in bivalve species. Accordingly, mussels Mytilus galloprovincialis were exposed to 10 μg Cu L(-1) as CuO nanoparticles and Cu(2+) for 15 days, and biomarkers of oxidative stress (superoxide dismutase, catalase and glutathione peroxidase), damage (lipid peroxidation) and metal exposure (metallothionein) were determined along with Cu accumulation in the digestive glands of mussels. Cu was linearly accumulated with time of exposure in mussels exposed to CuO nanoparticles, while in those exposed to Cu(2+) elimination was significant by day 15. Both forms of Cu cause oxidative stress with distinct modes of action. Exposure to CuO nanoparticles induces lower SOD activity in digestive glands compared to those exposed to Cu(2+), while CAT was only activated after 7 days of exposure to nano and ionic Cu, with contradictory effects after 15 days of exposure and GPX activities were similar. Lipid peroxidation levels increased in both Cu forms despite different antioxidant efficiency. Moreover, a linear induction of metallothionein was detected with time in mussels exposed to CuO nanoparticles, directly related to Cu accumulation, whereas in those exposed to Cu(2+) metallothionein was only induced after 15 days of exposure. Since only a small fraction of soluble Cu fraction was released from CuO nanoparticles, the observed effects seem to be related to the nano form of Cu, with aggregation as a key factor. Overall, our results show that the digestive gland is susceptible to CuO nanoparticles related oxidative stress, and is also the main tissue for their accumulation.
authors.affiliation: CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Tânia
authors.initials: T
authors.lastname: Gomes
authors.affiliation: CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Catarina G
authors.initials: CG
authors.lastname: Pereira
authors.affiliation: CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Cátia
authors.initials: C
authors.lastname: Cardoso
authors.affiliation: CBME, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: José P
authors.initials: JP
authors.lastname: Pinheiro
authors.affiliation: Department of Zoology & Animal Cell Biology, Scholl of Science and Technology, University of the Basque Country, E-48080 Bilbao, Spain.
authors.forename: Ibon
authors.initials: I
authors.lastname: Cancio
authors.affiliation: CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal. Electronic address: mbebian@ualg.pt.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Bebianno
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D003300:Copper / Q000493:pharmacokinetics* / Q000633:toxicity*; D004064:Digestive System / Q000378:metabolism*; D054750:Ecotoxicology; D005979:Glutathione Peroxidase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism; D049878:Mytilus / Q000187:drug effects* / Q000378:metabolism*; D053758:Nanoparticles / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D025341:Principal Component Analysis; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D008315:Malondialdehyde; D003300:Copper; D008668:Metallothionein; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C030973:cupric oxide