Cholinesterase and CYP1A biomarkers in resident flatfish from “contaminated” and “reference” sites in South Korea

Abstract

Masan Bay is a large harbour in the southern part of Korea which receives a wide range of industrial and sewage discharges and wastes from shipping activity. Previous studies have shown that there are high concentrations of PCBs and TBT (among other chemicals) in water and in sediments. In this study we assess the biological effects of pollution in Masan Bay on resident flatfish (marbled sole, Limanda yokahame) using the enzymatic “biomarkers” cytochrome P-450 1A (CYP 1A) induction, and acetyl- and butyryl-cholinesterase (AChE and BChE) inhibition. We have compared these indicators with those in fish from Haegeumgang, a “reference” site free of obvious sources of pollution, over an annual cycle. A transcript of approx. 3.5 kilobases was extracted from hepatic tissue and used for northern blot analysis of CYP1A1 mRNA, and since the deduced amino acid sequence of L. yokahamae CYP 1A showed high homology to other species, a general CYP1A antibody was used for western blot analysis. Fish from Masan Bay showed significant CYP 1A induction in spring and autumn compared to those from Haegeumgang. Brain AChE and muscle AChE and BChE were inhibited more than 30% in Masan fish in early summer but not later in the year. These results suggest that Masan fish are affected by continuous exposure to CYP 1A inducers, but by less persistent exposure to chemicals which inhibit AChE or BChE. Masan Bay is a large harbour in the southern part of Korea which receives a wide range of industrial and sewage discharges and wastes from shipping activity. Previous studies have shown that there are high concentrations of PCBs and TBT (among other chemicals) in water and in sediments. In this study we assess the biological effects of pollution in Masan Bay on resident flatfish (marbled sole, Limanda yokahame) using the enzymatic “biomarkers” cytochrome P-450 1A (CYP 1A) induction, and acetyl- and butyryl-cholinesterase (AChE and BChE) inhibition. We have compared these ind