Differences in enzymes (biomarkers) activities in fish after cage exposure in Drava and Danube Rivers (Croatia)

摘要

Biomonitoring using molecular biomarkers in fish is very important in environmental risk assessment. The need for sensitive and reliable methods to assess the impact of chemical pollution on the aquatic environment has generated considerable interest in biochemical and physiological indices of contaminant exposure and effects in fish (Stein et al. 1992). Two molecular biomarkers were used in this study: EROD (etoxyresorufin-G-deethylase) and AChE (acetyl-cholinesterase). Induction of EROD activity is a commonly used biomarker of exposure to xenobi-otics such as polycyclic aromatic hydrocarbons (PAH's), biphenyls, dibenzodioxines and dibenzofu-rans. The intensiveness of induction is proportional to their concentration in sediment (Narbonne et al. 1991) and in water. Furthermore, inhibition of AChE activity is a biomarker of effect to organophosphate and carbamate pesticides, detergents and cadmium in water, although some organic compounds simultaneously are EROD inducers and AChE inhibitors (Gal-gani et al. 1992, Payne et al. 1996, Guilhermino et al. 1998). We used the XAD-7 column adsorption technique to extract and concentrate lipophilic xeno-biotics (EROD inducers) from water samples and took advantage of its ability to adsorb aromatic compounds such as PAHs and heterocyclic amines (HCA) with two or more fused rings. The extracts obtained from XAD-7 column were used in the laboratory induct-test followed by EROD and AChE measurements in order to determine effects on their activities.