title: Metal and metallothionein distribution in different tissues of the Mediterranean clam Venerupis philippinarum during copper treatment and detoxification.
abstract: Filter feeding animals can accumulate large amount of contaminants in their body through particles filtered from seawater. In particular, copper is interesting since it plays important roles as co-factor of numerous proteins but its toxicity is well established, also because it can readily generate free radicals or oxidize cellular components through their redox activity. Its availability is tightly regulated within cells: it is immediately transferred to metallothionein (MT) that in turn provides efficient and specific mechanisms for its intracellular storage and transport. The aim of this study was to evaluate the acute effect of sublethal copper concentrations in Venerupis philippinarum, by studying the kinetics of copper, zinc (for its interactions at the sites of intake or elimination with the accumulation of other essential and not essential trace metals) and metallothionein accumulation under laboratory conditions. The time-course of metal accumulation/elimination is similar in digestive gland and gills and importantly it is dose-dependent. Both copper and zinc increase slowly within cells, reaching a maximum concentration at the end of the exposure period. During the detoxification period, the metal levels in digestive gland and gills rapidly decrease, with different kinetics in the two tissues. Positive correlations between metallothionein accumulation and copper or zinc concentrations have been verified in both treated groups. The obtained data demonstrated the involvement of MTs in detoxification strategies after a recovery period in clean seawater.
authors.affiliation: Department of Biology, University of Padova, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Santovito
authors.affiliation: Department of Biology, University of Padova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Boldrin
authors.affiliation: Department of Biology, University of Padova, Italy. Electronic address: paola.irato@unipd.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Irato
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000378:metabolism*; D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D004781:Environmental Exposure / Q000009:adverse effects; D005880:Gills / Q000378:metabolism; D007700:Kinetics; D019083:Mediterranean Region; D008668:Metallothionein / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry; D012758:Shellfish; D014018:Tissue Distribution / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity; D015032:Zinc / Q000378:metabolism* / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper; D008668:Metallothionein; D015032:Zinc
keywords: Copper; Detoxification; Metallothionein; Venerupis philippinarum; Zinc