DNA adducts in perch (Perca fluviatilis) from a creosote contaminated sitein the River Angermanalven, Sweden

Levels of hepatic DNA adducts, analysed by P-32-postlabelling, histopatholo gical lesions and organosomatic indices, were measured in perch (Perca fluv iatilis). The fish were caught at live sites in the river Angermanalven, Sw eden: one site known to be contaminated with creosote, sites downstream fro m the contaminated site and a reference site upstream. Perch were also caug ht at a long-distance reference site. The level of DNA adducts in fish from the creosote-contaminated site was 6.8 +/- 4.1 nmol mol(-1) nucleotides co mpared to 0.21 +/- 0.21 nmol mol(-1) nucleotides in fish from the long-dist ance reference site. The adduct level was also significantly increased comp ared to adduct levels in fish from the local reference site. Hepatocellular degeneration and macrophage aggregates were observed but did not correlate with a specific site in the river. No effects on organosomatic indices tha t correlated with distance from the contaminated site were observed. In the laboratory, perch Here exposed to an organic solvent extract prepared from sediment collected at the creosote-contaminated site or to benzo(a)pyrene (BaP) by oral administration. Perch treated with the extract had adduct pat terns very similar to those observed in perch from the contaminated field s ite. Two diagonal zones including 10-12 adduct spots were observed on the a utoradiograms. One adduct was tentatively identified by co-chromatography w ith a P-32-labelled standard of 7R,8S,9S-trihydroxy, 10R-(N-2-deoxyguanosyl 3'-phosphate)-7,8,9,10-tetrahydrobenzo(a)pyrene (BaPDE-dG-3'p) in two diff erent solvent systems. Autoradiograms derived from the BaP-exposed perch sh owed one major adduct and several less intense spots. The major BaP adduct had the same chromatographic properties as the standard BaPDE-dG-3'p adduct . This study shows that P-32-postlabelling analysis of DNA adducts in perch can be used as a sensitive indicator of exposure to genotoxic polycyclic a romatic hydrocarbons, and that comparison of DNA adduct patterns of fish ex posed in the field and laboratory can be used to determine the responsible source of pollutants. (C) 1999 Elsevier Science B.V. All rights reserved.