German doctors say Russian opposition leader Alexei Navalny was intoxicated by cholinesterase inhibitors. What is this substance? Explanations.
- Cholinesterase inhibitors, also called anticholinesterases, prevent the relaxation of neurotransmitters.
- They are the source of certain neurotoxic poisons such as sarin, agent XV or Novichok.
While demanding an end to corruption in Russia, Alexei Navalny has now been in a coma since August 22 in a hospital in Berlin (Germany). The reason for this fall of the very media opponent of Vladimir Putin? Probably poisoning with “cholinesterase inhibitors”. Why doctor dissects you the role of this substance.
Role
According to the Vidal Medical Dictionary, cholinesterase inhibitors, also known as anticholinesterases, are a “ssubstance that opposes the destruction of acetylcholine [neurotransmetteur, NDLR] by an enzyme, cholinesterase. Acetycholine is the main neurotransmitter used at the neuromuscular level and causes muscle contraction. It is also used by the autonomic nervous system and seems to play an important role in the process of memorization, learning and attention. But opposing the process of releasing neurotransmitters causes irrepressible muscle contractions, according to Julien Legros, CNRS research director at the Cobra laboratory in Rouen, specializing in the study of antidotes and techniques for neutralizing possible stocks of such agents. “An excitation of all neurons and all muscles”he describes.
Symptoms
These cholinesterase inhibitors can cause vomiting, incontinence, breathing difficulties, muscle weakness, paralysis, confusion, apnea, convulsions, then coma until death by asphyxiation. “The muscles are no longer able to contract and relax. They are seized with sorts of spasms. All muscles are affected, and the most crucial effect is on those responsible for breathing”explains toxicologist Alastair Hay of the University of Leeds, quoted by the British organization Science Media Center and taken up by AFP.
This neuronal blockage may or may not be reversible depending on the nature of the inhibitor used.
Famous neurotoxins
If this substance can be used in anesthesia-resuscitation, in treatments against glaucoma or Alzheimer’s disease and even in certain pesticides.
But it owes its fame to its military use as a chemical weapon, including “nerve agents”. It is the origin of sarin, agent XV, soman or Novichok. Agent XV was used at Kuala Lampur Airport (Malaysia) in 2017 in the assassination of Kim Jong-nam, a half-brother of North Korean dictator Kim Jong-un. Novichok was developed in the 1970s in Soviet Union, recalls Futura-sciences. It is made from individually authorized ingredients and does not reveal its toxicity once the components are mixed. In particular, he was used in 2018 in the assassination attempt on ex-Russian agent Sergei Skripal and his daughter, Yulia, in Salisbury (United Kingdom).
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