Suicide with organophosphates

The primary site of action of OPs is AChE, with which they interact as suicide substrates (see also Section 10.2.2 and Chapter 2, Figure 2.9). Similar to other B-type esterases, AChE has a reactive serine residue located at its active site, and the serine hydroxyl is phosphorylated by organophosphates. Phosphorylation causes loss of AChE activity and, at best, the phosphorylated enzyme reactivates only slowly. The rate of reactivation of the phosphorylated enzyme depends on the nature of the X groups, being relatively rapid with methoxy groups (tso 1-2 h), but slower with larger... 

Organophosphate poisonings are a particular problem in poorer countries, where lax controls, poor protective measures, and other problems contribute to exposure. The African country of Zimbabwe has experienced an epidemic of such poisonings, with a mortality rate from reported instances of around 8%.11 About three fourths of the adult poisonings were the result of suicide attempts, whereas poisoning in young children was predominantly from accidental ingestion. 

Wesseling, C, van Wendel de Joode, B., Keifer, M., et al., 2010. Symptoms of psychological distress and suicidal ideation among banana workers with a history of poisoning by organophosphate or n-methyl carbamate pesticides. Occup. Environ. Med. 67, 778-784. 

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