Cholinesterases (ChEs) are widely distributed in the animal kingdom. In invertebrates, ChES appear to be a group of related enzymes with widely varying properties; substrate specificity and patterns of inhibition are especially variable. Among these enzymes, acetylcholinesterases (AChEs) (E.C. 220.127.116.11) preferentially hydrolyse acetylthiocholine as substrate and are very sensitive to eserine inhibition. AChEs are involved in synaptic transmission and their main function is the hydrolysis of acetylcholine, the mediator of cholinergic synapses in the nervous system. While most of the studies about invertebrate ChEs were devoted to free-living and parasitic nematods and insects, few studies have been conducted on marine invertebrates. AChE is the target of organophosphate and carbamate pesticides. These compounds inhibit the activity of AChE; thus the neurotransmitter accumulates ; its action is enhanced and it finally causes death. The AChE activity of choosen species of marine invertebrates can be used as a biochemical marker of the effects of neurotoxic contaminants (including organophosphate and carbamate pesticides but also mixtures of pesticides and metals).
Buy this Article