Ethoxyresorufin-O-deethylase (EROD) activity and bile metabolites as contamination indicators in Baltic Sea perch: Determination by HPLC

Exposure of Baltic Sea perch (Perca fluviatilis) to organic contaminants was investigated by means of liver enzyme activity, measured as ethoxyresorufin-O-deethylase (EROD) activity, and PAH metabolites excreted to bile. Female perch used in the study were caught in coastal waters of the western Gulf of Finland. Reaction conditions were optimised for determination of EROD activity in liver. A high-performance liquid chromatography (HPLC) method with fluorescence detection was developed to separate the interfering fluorescent signal from the signal due to EROD activity. EROD activity in perch varied within a concentration range of 0.30–14 pmol min−1 mg−1 protein. Recent PAH exposure was indicated in enhanced levels of the bile metabolite 1-hydroxypyrene, which varied between 213 and 1149 μg kg−1. No correlation was indicated between hepatic EROD activity and concentration of 1-hydroxypyrene.