title: Differences in metal sequestration between zebra mussels from clean and polluted field locations.
abstract: Organisms are able to detoxify accumulated metals by, e.g. binding them to metallothionein (MT) and/or sequestering them in metal-rich granules (MRG). The different factors involved in determining the capacity or efficiency with which metals are detoxified are not yet known. In this work we studied how the sub-cellular distribution pattern of cadmium, copper and zinc in whole tissue of zebra mussels from clean and polluted surface waters is influenced by the total accumulated metal concentration and by its physiological condition. Additionally we measured the metallothionein concentration in the mussel tissue. Metal concentration increased gradually in the metal-sensitive and detoxified sub-cellular fractions with increasing whole tissue concentrations. However, metal concentrations in the sensitive fractions did not increase to the same extent as metal concentrations in whole tissues. In more polluted mussels the contribution of MRG and MT became more important. Nevertheless, metal detoxification was not sufficient to prevent metal binding to heat-sensitive low molecular weight proteins (HDP fraction). Finally we found an indication that metal detoxification was influenced by the condition of the zebra mussels. MT content could be explained for up to 83% by variations in Zn concentration and physiological condition of the mussels.
authors.affiliation: Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
authors.forename: Judith
authors.initials: J
authors.lastname: Voets
authors.forename: Erik Steen
authors.initials: ES
authors.lastname: Redeker
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
authors.forename: Lieven
authors.initials: L
authors.lastname: Bervoets
mesh_terms: D000818:Animals; D002105:Cadmium Poisoning / Q000378:metabolism; D002458:Cell Fractionation / Q000379:methods; D003300:Copper / Q000493:pharmacokinetics / Q000506:poisoning; D049875:Dreissena / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods; D000075322:Heavy Metal Poisoning; D008658:Inactivation, Metabolic; D008668:Metallothionein / Q000378:metabolism; D019216:Metals, Heavy / Q000493:pharmacokinetics*; D018709:Statistics, Nonparametric; D013347:Subcellular Fractions / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics* / Q000506:poisoning; D015032:Zinc / Q000493:pharmacokinetics / Q000506:poisoning
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D003300:Copper; D008668:Metallothionein; D015032:Zinc