MEPS 205:195-206 (2000)  -  doi:10.3354/meps205195

Induction and elimination of bulky benzo[a]pyrene-related DNA adducts and 8 oxodGuo in mussels Mytilus galloprovincialis exposed in vivo to B[a]P contaminated feed

F. Akcha1, T. Burgeot2, H. Budzinski1, A. Pfohl-Leszkowicz3, J.-F. Narbonne1

1Laboratoire de Physico- et Toxicochimie des Systèmes Naturels, UPRESA 5472 CNRS, Université de Bordeaux 1, Avenue des Facultés, 33405 Talence, France
2IFREMER, Laboratoire des Polluants chimiques, Rue de l¹Ile d¹Yeu, 44300 Nantes Cedex, France
3ENSAT, Laboratoire de Toxicologie et de Sécurité Alimentaire, Avenue de l¹Agrobiopôle, BP 107, Auzeville Tolosane, 31326 Castanet-Tolosane Cedex, France

ABSTRACT: With the aim of developing biomarkers of polycyclic aromatic hydrocarbon (PAH) genotoxicity for biomonitoring of the marine environment, the formation of DNA adducts and oxidative DNA damage was studied in the sentinel organism Mytilus. Mussels M. galloprovincialis were exposed for 21 d to different doses of benzo[a]pyrene (B[a]P) (50 and 100 mg B[a]P kg-1 dry wt mussel d-1) via trophic intake. The kinetics of B[a]P concentration in whole mussel tissues was determined in both groups, and a dose-response study was conducted for both gill B[a]P-related DNA adducts and 8-oxo-7,8-dihydro-2¹-deoxyguanosine (8-oxodGuo) formation in gill and digestive gland DNA. Exposure was followed by a 10 d depuration period to study mussel recovery. Although B[a]P was absorbed and bioaccumulated to very high concentrations (>300 mg B[a]P kg-1 dry wt mussel), plateau values were not reached in either assay group. Regardless of the exposure dose of B[a]P, several bulky DNA adducts were induced in the typical PAH diagonal radioactive zone. For both doses, positive correlations were found between total DNA adduct level and both exposure time and B[a]P concentration in whole mussel tissues. DNA repair during depuration differed among the B[a]P-induced DNA adducts. B[a]P exposure had no effect on gill 8-oxodGuo levels, but led to a significant dose-dependent increase in the number of oxidative lesions in mussel digestive gland DNA. The decrease with depuration in digestive gland 8-oxodGuo levels to control values was indicative of the mussels¹ ability to recover from oxidative DNA damage.


KEY WORDS: B[a]P · Mussel · DNA adducts · 8-oxodGuo · DNA repair


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