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(80-69) ISIS - Genotoxicity testing of marine sediments with fish cells and the comet assay. Ulrike, Kammann*,1, Biselli, Scarlett3, Danischewski, Dirk1, Huehnerfuss, Heinrich2, Reineke, Ninja2, Theobald, Norbert3, 1 Federal Research Centre for Fisheries, Hamburg, Germany3 German Federal Maritime and Hydrographic Agency, Hamburg, Germany2 University of Hamburg, Germany ABSTRACT- The concern about effects of genotoxic pollutants on marine fish species makes fish-derived cells a useful tool for environmental toxicology. Fish cells (Epithelioma papulosum cyprini, EPC) were exposed in vitro to different concentrations of organic sediment extracts from the North Sea. The cells were analysed for DNA strand breaks and alkali labile sites with the comet assay. Comets were scored visually according to the relative intensity of the fluorescence in the tail. The EC50 of sediment extracts was calculted from the results of 5 or more concentrations. EC50 ranged from 7 to 307 mg sediment dry weight / ml assay volume. These differences seem to be related to the amount of organic matter as well as to contaminants analyzed in the sediment. To identify the substances causing the genotoxic effects, sediment extracts from the North Sea have been subjected to a 3-step fractionation procedure. The resulting fractions have been tested with the comet assay. Significant genotoxic effects were present in fractions which contain substances with a higher polarity. Less polar substances like PCBs or PAHs are not likely to cause the observed genotoxic effects in fish cells. Our results show that it is possible to detect genotoxic effects of marine sediment extracts from the North Sea with an in vitro comet assay based on EPC cells, and combine marine sediment extracts with a bioassay-directed fractionation. ISIS 'Identification of sediment bound contaminants from North and Baltic Sea', is supported by a grant from the German Federal Ministry of Education and Research. Key words: comet assay, genotoxicity, fish cells, sediment |
