Present at the neurosynaptic junctions, acetylcholinesterase breaks acetylcholine into acetyl and choline fragments. The poisonous effects of organophosphorous and carbamate pesticides come about through the inhibition of cholinesterase, an enzyme produced in the liver. One form, acetylcholinesterase, can be found at the neurosynaptic junctions while another, butyryl cholinesterase, is primarily located in the plasma and pancreas, although small quantities of it exist in all tissues including our blood. Organophosphate Insecticides Organophosphorus compounds differ from one another in many important respects, although chemically, all can be considered to be derivatives of phosphoric or thiophosphoric acids. They differ widely in inherent toxicity and in their ability to penetrate the skin.
Some organophosphates act directly while others require activation by enzymes within the body.
Some are destroyed and eliminated more rapidly than others. Also, they differ with respect to the manner of their reaction with the cholinesterase enzyme. Organophosphate pesticides inhibit cholinesterase by forming covalent chemical bonds through a process called phosphorylation. Spontaneous enzymatic regeneration half-lifes may take days to months long. As with carbamates, the nature of the organophosphate involved, the dose received and the duration of exposure all affect the period for regeneration to occur.