Acetylcholinesterase inhibition organophosphate nerve agents

FIGURE 62.1. OPs bind to and inhibit acetylcholinesterase (AChE), the enzyme responsible for degrading the neurotrans-mitter, acetycholine (ACh), into choline and acetate. When AChE is inhibited by an organophosphate nerve agent, the subsequent reduced hydrolysis of ACh results in an accumulation of ACh within the synaptic cleft and overstimulation of the post-synaptic nerve. Seizures and possibly paralysis and/or death may occur. 

Although bicyclophosphates do not inhibit acetylcholinesterase, they exhibit a synergistic toxic effect with materials that do. Individuals who have had previous exposure to cholinesterase inhibitors such as nerve agents and commercial organophosphate or carbamate pesticides may be at a greater risk from exposure to bicyclophosphates. 

Field First Aid Nerve agents are the most toxic of the known chemical warfare agents. Chemically similar to organophosphate pesticides, their method of acting is to inhibit acetylcholinesterase enzymes. Individuals whose skin or clothing is contaminated with... 

The enzyme acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylcholine to acetate and choline to terminate nerve impulse transmission at cholinergic synapses. This enzyme binds nerve agents such as VX and sarin. Inhibition of AChE by these compounds and the closely related organophosphate pesticides results in constant... 

Organophosphate Ester Hydraulic Fluids. The biomarkers of effects after exposure to organophosphate ester hydraulic fluids are well established in cases of delayed neuropathy (clinical signs of peripheral neuropathy). Further study would be helpful to determine whether certain effects (such as diarrhea after oral exposure) are due to direct action of the toxic agent on the target organ or to inhibition of acetylcholinesterase at the acetylcholine nerve receptor site on the organ. 

---