J. Phys. IV France 107 (2003) 197
DOI: 10.1051/jp4:20030276

Sub-cellular partitioning of essential and non-essential metals in a freshwater mollusc, Pyganodon grandis, collected in the field along a polymetallic environmental gradient

E. Bonneris^{1, 2}, A. Giguère¹, S. Masson¹ and P.G.C. Campbell<sup>1

1</sup>  Institut National de la Recherche Scientifique, INRS Eau, Terre et Environnement, Université du Québec, CP. 7500, Sainte-Foy, Québec, G1V 4C7, Canada
²  Unité Mixte de Recherche INRA-DGER, École Nationale Vétérinaire de Lyon, Laboratoire d'Écotoxicologie, 1 avenue Bourgelat, BP. 83, 69290 Marcy-l'Étoile, France

Abstract
The cellular alterations normally induced by metals at high concentrations can be prevented by detoxification processes [1] such as sequestration into cellular compartments (calcium concretions, lysosomes, etc.) or their binding to specifie cellular ligands like metallothionein [2]. The aim of this project was to study and compare the subcellular partitioning of three metals (Cd, Cu, Zn) in gills of a freshwater mollusc, Pyganodon grandis , collected along a polymetallic environmental gradient (nine lakes in the Rouyn-Noranda area, Abitibi, QC, Canada). Differential centrifugation was used to partition metals among different subcellular fractions. In the gills, along the environmental metal gradient, total tissue metal concentrations were positively correlated with concentrations in the granule fraction; gill tissues contained high amounts of calcium concretions, which acted as preferential sites for sequestration of the three metals. An increase in Cd concentration was observed in the heat stable proteins fraction (including metallothionein), but not in the heat-denatured proteins fraction, suggesting that Cd-induced cell injury could be prevented by the involement of multiple cellular compartments in a protective role.

© EDP Sciences 2003