Neurotransmitters toxic gases

Nerve Agent Substances that interfere with the central nervous system. Organic esters of phosphoric acid used as a chemical warfare agent because of their extreme toxicity (tabun-GA, sarin-GB, soman-GD, GF, and VX). All are potent inhibitors of the enzyme, acetylcholinesterase, which is responsible for the degradation of the neurotransmitter, acetylcholine in neuronal synapses or myoneural junctions. Nerve agents are readily absorbed by inhalation and/or through intact skin. 

GA, a unitary chemical munition, inhibits AChE, the enzyme responsible for the breakdown of the neurotransmitter ACh. When inhaled, its toxicity is half that of sarin. It depresses plasma and RBC-AChE activities significantly in the blood. At 20-25% of red blood cell AChE baseline, the effect of the nerve agent becomes noticeable. There is no evidence of systemic toxicity other than the cholinesterase activity (Parker et al, 1990 Munro et al, 1994). GA has not been shown to produce OPIDN except at extremely high doses. The cardiac effect of GA conforms to OP-caused arrhythmias and AV block. 

Toxicity The agents GA, GB, and VX are rapidly acting, lethal nerve agents. They directly affect the nervous system and are toxic as liquids and vapors. They are organophosphorus esters that inhibit acetylcholinesterase, an enzyme that prevents the accumulation of the neurotransmitter acetylcholine at the nerve synapses. When too much acetylcholine is present, convulsion and death may result. 

The principal nerve agents. Sarin (GB), Soman (GD), Tabun (GA) and V-agents, are all organophosphorus compounds that inhibit the enzyme cholinesterase which is responsible for breaking down acetylcholine, a neurotransmitter. Nerve agents are toxic both by inhalation and by absorption through the skin. Symptoms include droohng, dilated pinhead pupils, headache, involuntary defecation, and a runny nose. Death is caused by cardiac arrest or respiratory failure. 

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