Peripheral nervous system organophosphorus compounds

Randall, J.C., Yano, B.L., and Richardson, R. J., Potentiation of organophosphorus compound-induced delayed neurotoxicity (OPIDN) in the central and peripheral nervous system of the adult hen distribution of axonal lesions, J. Toxicol. Environ. Health., 51(6), 571-590,1997. 

The inhibition of AChE leads to the accumulation of the neurotransmitter ACh in synapses of the central and peripheral nervous systems and over-stimulation of post-synaptic cholinergic receptors. Exposure to even small amounts of an organophosphorus compound can be fatal as the poison causes seizures, convulsions and lesions of the central nervous system. The current standard treatment for poisoning usually consists of combined administration of anticholinergic drugs (preferably atropine) and AChE reactivators (called oximes). 

The nerve gases are powerful inhibitors of the enzyme acetylcholinesterase (AChE), which causes rapid hydrolysis of acetylcholine. They are also inhibitors of butyryl-choUnesterase and carboxylesterase. Acetylcholine is the chemical that is released to transmit nerve impulses in the central nervous system and also at several peripheral locations. Once the impulse is transmitted, acetylcholine must be removed instantaneously for proper functioning of the nervous system. Such removal is done by the enzyme AChE, which is found extensively in nervous system and many non-nervous tissues. Nerve gases and other organophosphorus compounds bind... 

It is known that human exposure to organophosphorus compounds can result in a variety of acute toxic effects. These arise primarily as a result of the inhibition of acetylcholinesterase. Signs of acute toxicity are due to effects on the central nervous system (anxiety, ataxia, hypotension), to muscarinic effects (wheezing, cough, rhinitis) and to nicotinic effects (muscle weakness, mydriasis and tachycardia). Other acute effects include chest tightness, abdominal cramps, confusion and convulsions. With some organophosphorus compounds, a specific syndrome may develop. This is delayed peripheral neuropathy or OP-induced delayed neuropathy (OPIDN). (For a more detailed discussion on the toxicity of organophosphorus compounds see Chapter 10.)... 

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