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(22-11) Characterization of exposure and effect biomarkers in the European eel Anguilla anguilla. Corsi, Ilaria*,1, Mariottini, Michela1, Bonacci, Stefano1, Focardi, Silvano1, Frenzilli, Giada2, Nigro, Marco2, Gorbi, Stefania3, Regoli, Francesco3, 1 Dipartimento di Scienze Ambientali, Siena, Italy2 Dipartimento Morfologia Umana e Biologia Applicata, Pisa, Italy3 Istituto Biologia e Genetica, Ancona, Italy ABSTRACT- The characterization of typical bioindicator organisms is strongly needed in Mediterranean coastal lagoons for monitoring both the presence and the biological impact of pollutants in such delicate ecosystems. The aim of this work was to investigate the natural variability of several molecular and cellular responses in European eels (Anguilla anguilla) and the sensitivity of this species in revealing the occurrence of environmental disturbance. The levels of metallothioneins and the induction of cytochrome P450 (EROD and BaPMO activities) were analyzed as specific biomarkers of exposure to selected pollutants while the efficiency of antioxidant defenses was considered to reveal toxicity mediated by enhanced ROS generation. Variations of the main cellular antioxidants (e.g. catalase, glutathione peroxidases, glutathione reductase, glutathione S-transferase, glutathione) were integrated with the total oxyradical scavenging capacity (TOSC), which provides a quantifiable value of the overall resistance/susceptibility to different forms of oxyradicals (as peroxyl radical and hydroxyl radical). The possible involvement of oxyradicals in inducing damages at DNA level was investigated by analyzing the induction of DNA strand breakage (Comet assay) and apoptosis. All the above parameters were analyzed on a seasonal basis in eels sampled from a moderately polluted coastal lagoon which enable to evaluate sensitivity of these organisms in various periods; dose-response relationships were also characterized in laboratory conditions where the organisms were exposed to increasing concentrations of benzo[a]pyrene, Aroclor 1254, b-naphtoflavone or 2,3,7,8-tetrachlorodibenzo-p-dioxin. Key words: European eel, comet assay, metallothioneins, antioxidants |
