Biliary PAH and Alkylphenol Metabolites, Biomarker Enzyme Activities, and Gene Expression Levels in the Deep-Sea Fish Alepocephalus rostratus

22 pages, 3 figures, 3 tables

Biliary polycyclic aromatic hydrocarbon (PAH) and alkylphenol (AP) metabolites, hepatic gene expression, and corresponding enzyme activities were determined in the deep-sea fish Alepocephalus rostratus from two sites within the Mediterranean. Biliary metabolites included the hydroxylated PAH metabolites (OH-PAHs) 1-naphthol, 2-naphthol, 9-fluorenol, 9-phenanthrol, and 1-pyrenol and the APs 4-nonylphenol (NP) and 4-tert-octylphenol (OP). Five biomarker genes, namely, cytochrome P450 1A (CYP1A), vitellogenin (Vtg), catalase (CAT), Cu/Zn-superoxide-dismutase (Cu/Zn-SOD), and glutathione reductase (GR), were quantified using qRT-PCR. Moreover, corresponding enzyme activities (ethoxyresorufin-O-deethylase (EROD), CAT, SOD, and GR) were also determined. The ΣOH-PAHs detected ranged from 21.1 to 300.3 ng/g bile and were mainly composed of 1-naphthol. Both NP and OP metabolites were detected in all samples with concentrations ranging from 17.4 to 107.2 ng/g bile and 4.9 to 17.3 ng/g bile, respectively, and levels were significantly higher in samples from the western Mediterranean (WM) compared to those from the Catalan slope (CS). Accordingly, gene expression was significantly induced in male fish from the WM; however, these results were not reflected in enzyme activity levels. In particular, males caught at 2000 m in the WM exhibited 35-times higher Vtg levels compared to those from the CS, suggesting that endocrine-disrupting effects may potentially be occurring in such remote environments as the deep-sea

The present study was funded by the Spanish Science and Technology Ministry projects PROMETEO (CTM2007-66316-C02-02/MAR), BIOFUN (CTM2007-28739-E/MAR) and the HERMIONE project (EC-FP7 contract number 226354). Samuel Koenig holds a PhD grant (AFR 08/067) from the Fonds National de la Recherche (FNR), Luxembourg. The authors wish to thank the DeepMed Research Group (ICM-CSIC) and the R/V Garcia del Cid (CSIC) and R/V Sarmiento de Gamboa (CSIC) crews for helping with sampling. Furthermore, the authors acknowledge the help by R. Chaler, D. Fanjul, M. Comesaña with GC-MS instrumental analysis, as well as the technical assistance by N. Asker and M. Hultman with qPCR analysis

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