Induction of CYP1A and porphyrin accumulation in fish hepatoma cells (PLHC-1) exposed to sediment or water from a PCB-contaminated lake (Lake Kernaala, Finland)

Surficial sediments and lake waters from a polychlorinated biphenyl (PCB) polluted lake, Lake Kernaala, were monitored with a fish hepatoma cell line (PLHC-1). The cells were exposed to the lipid soluble fraction of the samples in 48-multiwell plates. 7-Ethoxyresorufin O-deethylase (EROD) activity, total protein content and porphyrin content were detected with a plate reader. Lake Kernaala sediment extracts induced CYP1A and porphyrins in the cells more than the reference sediment extracts from Lake Alasjärvi. ED50s for EROD activity were achieved at lower sediment extract doses than ED50s for porphyrin content. The pollutants were in a concentrated form in the sediment extracts. Thus, these samples more likely expressed the potential rather than the actual hazard of the chemicals. Lake Kernaala water extracts did not increase EROD activity in the cells at doses that corresponded to the actual concentration in the lake. However, the water extracts elevated EROD activity when concentrated and in this way expressed CYP1A induction. Based on our findings in sediment and water exposures, PLHC-1 cells are suggested for use in monitoring and comparing different water areas.