Environmental contaminants and biochemical response in eel exposed to Po river water

Groups of eels (Anguilla anguilla) were exposed to Po river water under con trol conditions at "la Casella" Fluvial Hydrobiology Station for 30-day per iods between November and May. At the end of the exposure period, fish were sacrificed and cytochrome P4501A was evaluated in liver microsomes using b oth catalytic (EROD) and semiquantitative immunodetection (ELISA) assays. A t the same time, water samples were taken for chemical analyses of PCBs, PA Hs and pesticides. Eel was chosen as bio-indicator on the bases of experime nts on cytochrome P450 expression and activity under basal or induced condi tions and in consideration of the ecological and economic relevance and eas e of handling, Low levels of cytochrome P450 during Winter were followed by a step increase during Spring, associated with a substantial concentration increase of agrochemicals. A good correlation was found between measuremen ts of cytochrome P4501A by EROD and ELISA in dose-effect experiments, howev er, ELISA showed a higher sensitivity. Immunochemical techniques may be use d in addition to enzyme activity measurements both to detect lower levels o f cytochrome P450 induction (where they proved more sensitive) and as quali ty control. These results suggest that measurement of cytochrome P4501A und er controlled conditions, using eel as bio-indicator, can be a useful tool in monitoring Po river ecosystems. (C) 2000 Elsevier Science Ltd. All right s reserved.