The use of cholinesterases in ecotoxicology

Abstract

Cholinesterase (ChE) is one of the most employed biomarkers in environmental analysis. Among ChEs, potentially the most significant in environmental terms is acetylcholinesterase (AChE), an enzymatic form that terminates the nerve impulse. Because of its physiological role, AChE has long been considered a highly specific biomarker for organisms exposed to anticholinesterasic agents, primarily agrochemicals (organophosphate and carbamate pesticides). The effects of these pesticides depend upon their selective inhibition of AChE. Because large amounts of such pesticides are employed, it is plausible that they exert neurotoxic effects on some non-target species. Therefore, AChE is among the most valuable of diagnostic tools that can be used to verify exposure to such chemical agents. It is well known that assays are available for use in quantifying AChE in multiple tissues of several test organisms. Enzymes other than AChE (e.g., butyrylcholinesterase and carboxylesterases) have also been used as putative markers for detecting the environmental presence of contaminating compounds. Researchers must use a step-bystep approach to identify the most prominent cholinesterasic form present in a given species, so that this form can be distinguished from others that may interfere with its use. Such fundamental work must be completed prior to using ChEs for any monitoring to assess for anticholinesterasic effects. © 2011 Springer Science+Business Media, LLC.