Correlative changes in metabolism and DNA damage in turbot (Scophthalmus maximus) exposed to benzo[a]pyrene

Juvenile turbot (Scophthalmus maximus) were injected intraperitonteally with either corn oil or 5 mg/kg benzo[a]pyrene (BaP) dissolved in corn oil and sampled 1 and 3 days after injection. After 1 day, no elevation of 7-ethoxyresorufin O-deethylase (EROD) activity was observed, however bile metabolites (BaP-7,8 dihydrodiol representing 70% of the total metabolites) and a single hepatic DNA adduct spot (0.47 adducts/108 nucleotides) identified by 32P-postlabelling were formed. No BaP metabolites or DNA adducts were observed in either control or carrier control fish. Fish sampled after 3 days reported 5-fold higher (P <0.05) levels of EROD activity, a shift in the bile metabolite profile towards BaP phenol formation (1OH and 3OH BaP comprising up to 60% of total metabolites detected) and the formation of two adduct spots (0.86 and 0.71 adducts/108 nucleotides). These results show that BaP can be metabolised and form hydrophobic DNA adducts in turbot without EROD elevation. Following EROD elevation, a shift in the profile of both BaP metabolites and BaP metabolite–DNA interactions occurs indicative of other oxidative processes.