VR (nerve agent)
Encyclopedia
VR is a "V-series" nerve agent
closely related (isomer
) to the better-known VX nerve agent
.
The development of VR started in the late 1950s by a team from the Soviet Union's Scientific Research Institute No. 42 (NII-42). Sergei Zotovich Ivin, Leonid Soborovsky, and a female chemist named Iya Danilovna Shilakova jointly developed this analogue of VX. They completed their work in 1963 and were later awarded the Lenin Prize
for their achievement. A binary weapon comprising two less toxic precursors which mixed during flight to form Substance 33 was later developed by a team led by Nikolai Kuznetsov, for which they were awarded the 1990 Lenin Prize.
In 1972 the Soviets opened a manufacturing plant for VR in Novocheboksarsk
. All facilities in USSR produced 15,557 tons of VR according to their declaration to the Organisation for the Prohibition of Chemical Weapons
(OPCW), although most if not all of this has now been destroyed under disarmament treaties.
VR has similar lethal dose levels to VX (between 10-50 mg) and has similar symptoms and method of action to other nerve agents that act on cholinesterase
, and treatment remains the same. However the window for effectively treating second generation V series seizure
s is shorter, as they rapidly denature the acetylcholinesterase protein in a similar manner to soman
, making treatment with the standard nerve gas antidote pralidoxime
ineffective unless it is given very soon after exposure. Pre-treatment with pyridostigmine
prior to exposure, and treatment with other drugs such as atropine
and diazepam
after exposure, will reduce symptoms of nerve agent toxicity but may not be sufficient to prevent death if a large dose of nerve agent has been absorbed. In addition to the standard seizures, some of the second generation V series agents are known to cause coma
s.
Nerve agent
Nerve agents are a class of phosphorus-containing organic chemicals that disrupt the mechanism by which nerves transfer messages to organs...
closely related (isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
) to the better-known VX nerve agent
VX (nerve agent)
VX, IUPAC name O-ethyl S-[2-ethyl] methylphosphonothioate, is an extremely toxic substance whose only application is in chemical warfare as a nerve agent. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations in UN Resolution 687...
.
The development of VR started in the late 1950s by a team from the Soviet Union's Scientific Research Institute No. 42 (NII-42). Sergei Zotovich Ivin, Leonid Soborovsky, and a female chemist named Iya Danilovna Shilakova jointly developed this analogue of VX. They completed their work in 1963 and were later awarded the Lenin Prize
Lenin Prize
The Lenin Prize was one of the most prestigious awards of the USSR, presented to individuals for accomplishments relating to science, literature, arts, architecture, and technology. It was created on June 23, 1925 and was awarded until 1934. During the period from 1935 to 1956, the Lenin Prize was...
for their achievement. A binary weapon comprising two less toxic precursors which mixed during flight to form Substance 33 was later developed by a team led by Nikolai Kuznetsov, for which they were awarded the 1990 Lenin Prize.
In 1972 the Soviets opened a manufacturing plant for VR in Novocheboksarsk
Novocheboksarsk
Novocheboksarsk is a city in the Chuvash Republic, Russia, located about east of the republic's capital city of Cheboksary, on the southern bank of the Volga River. Population: -History:...
. All facilities in USSR produced 15,557 tons of VR according to their declaration to the Organisation for the Prohibition of Chemical Weapons
Organisation for the Prohibition of Chemical Weapons
The Organisation for the Prohibition of Chemical Weapons is an intergovernmental organization, located in The Hague, Netherlands. The organization promotes and verifies the adherence to the Chemical Weapons Convention which prohibits of the use of chemical weapons and requires their destruction...
(OPCW), although most if not all of this has now been destroyed under disarmament treaties.
VR has similar lethal dose levels to VX (between 10-50 mg) and has similar symptoms and method of action to other nerve agents that act on cholinesterase
Cholinesterase
In biochemistry, cholinesterase is a family of enzymes that catalyze the hydrolysis of the neurotransmitter acetylcholine into choline and acetic acid, a reaction necessary to allow a cholinergic neuron to return to its resting state after activation.-Types:...
, and treatment remains the same. However the window for effectively treating second generation V series seizure
Seizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
s is shorter, as they rapidly denature the acetylcholinesterase protein in a similar manner to soman
Soman
Soman, or GD , is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the cholinesterase enzyme. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN...
, making treatment with the standard nerve gas antidote pralidoxime
Pralidoxime
Pralidoxime or 2-PAM, usually as the chloride or methiodide salts, belongs to a family of compounds called oximes that bind to organophosphate-inactivated acetylcholinesterase. It is used to combat poisoning by organophosphates or acetylcholinesterase inhibitors , in conjunction with atropine and ...
ineffective unless it is given very soon after exposure. Pre-treatment with pyridostigmine
Pyridostigmine
Pyridostigmine is a parasympathomimetic and a reversible cholinesterase inhibitor. Since it is a quaternary amine, it is poorly absorbed in the gut and does not cross the blood-brain barrier, except possibly in stressful conditions.-Mode of action:...
prior to exposure, and treatment with other drugs such as atropine
Atropine
Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...
and diazepam
Diazepam
Diazepam , first marketed as Valium by Hoffmann-La Roche is a benzodiazepine drug. Diazepam is also marketed in Australia as Antenex. It is commonly used for treating anxiety, insomnia, seizures including status epilepticus, muscle spasms , restless legs syndrome, alcohol withdrawal,...
after exposure, will reduce symptoms of nerve agent toxicity but may not be sufficient to prevent death if a large dose of nerve agent has been absorbed. In addition to the standard seizures, some of the second generation V series agents are known to cause coma
Coma
In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
s.