Biomarkers and trace metals in the digestive gland of indigenous and transplanted mussels, Mytilus galloprovincialis, in Venice Lagoon, Italy

The aim of this study was to investigate the cellular and biochemical respo nse of mussels, Mytilus galloprovincialis, transplanted from a relatively p ristine site to a polluted one and vice versa in the Lagoon of Venice (nort heast of Italy) and to apply auto-metallography, a rapid and sensitive hist ochemical technique, to determine the bio-available fraction Of heavy metal s accumulated in the body tissues of organisms. Animal digestive glands hav e been used for morphological analyses (lysosomal volume, surface and numer ical density, mean epithelial thickness, mean diverticular and luminar radi us), autometallographical black silver deposits quantification and biochemi cal assays (superoxide dismutase and catalase activity). Furthermore, heavy metal content was determined by atomic absorption spectrophotometry (AAS) using standard procedures. The overall results indicate a direct influence of the environment in the thinning of the digestive cells and in the increa sing number of lysosomes in mussels from the more polluted site. These data are in agreement with the metal content in digestive cell lysosomes as det ermined by autometallography, whereas AAS measurements show less significan t differences. (C) 2000 Elsevier Science Ltd. All rights reserved.