Inhibition of cholinesterase activity in vitro and vivo -a case study in Masan Bay

Abstract

Cholinesterases (ChEs) are interested in the use of ChE as a \\\"biomarker\\\" as evidence accumulated that ChE activity in fish was inhibited at sites not obviously contaminated by organophosphate or carbamate pesticides. Although the chemical cause of such inhibition is still unidentified, ChE is being used as a bioassay to identify potentially contaminated sites which can be examined in more detail using the approaches of analytical chemistry. We have characterised the cholinesterases (ChE) in marbled sole (Limanda yokahamae) with the aim of using ChE's in this species to assess the effects of certain marine contaminants in northeast Asian waters. Since most contaminants of concern are sediment-bound, the selection criteria were that the fish should be preferably a benthic species (thus maximizingits exposure to contaminated sediment). In this study, we describe ChE activity in marbled sole from an industrial harbour, the inner reaches of Masan Bay with that in sole from a reference site, Haegeumgang, in Geoje Island. In late spring 2004, there are clear difference in ChE activity, with brain AChE being reduced by about 30%, muscle AChE 50%. A similar high level of enzyme inhibition was observed in muscle (BChE by 50 %) compared to those from Haegeumgang. In contrast, Masan bay marbled sole didn’t differ from Haegeumgang fish on ChEs activity in other seasons. This suggests that the Masan fish had different ChE affection than those on Haegeumgang in spring 2004 .