Botulinum toxin , ( botulinum toxin, botulism toxin ) - a protein neurotoxin produced by the bacteria Clostridium botulinum . The strongest organic poison from the known toxins organic toxins [1] and one of the most toxic substances. The ingress of botulinum toxin into the digestive system of the body causes severe toxic damage - botulism , which in vivo occurs in humans , horses , birds , less often - cattle , fur animals.
| Botulinum toxin | |
|---|---|
 | |
 | |
| Are common | |
| Abbreviations | Bont |
| Traditional names | botulinum toxin |
| Chem. formula | C 6760 H 10447 N 1743 O 2010 S 32 |
| Physical properties | |
| Molar mass | 149322 g / mol |
| Classification | |
| Reg. CAS number | 93384-43-1 |
| Reg. EINECS number | |
| Reg. EC number | 3.4.24.69 |
| Security | |
| LD 50 | mouse, abdominal, ng / kg weight
|
| Toxicity | Extremely toxic  |
Botulinum toxin according to the pathogen serovar is divided into types A, B, C1, C2, D, E, F, G, H of which type A is most common. Semi-lethal dose in various serovars averages about 1 ng / kg weight [2] .
Toxicity
Botulinum toxin is one of the most complex proteins synthesized by a living organism. Its mass is about 150 thousand atomic mass units , which is three times the typical size of the protein chain, few proteins (for example, titin ) exceed this average size.
The closest poison to botulinum toxin, both in structure and in strength, is tetanospasmin . It is produced by another type of clostridia - Clostridium tetani , a tetanus pathogen. Nevertheless, it is inferior to botulinum toxin in toxicity due to the lower molecular weight - 140 thousand a. eat.
Effects on the body
Clostridia botulinum, being obligate anaerobes , can reproduce only in conditions of complete absence of oxygen . As a rule, these are canned and sausage products (especially canned fried mushrooms and meat and fish prepared in large pieces with damage on the surface). The exotoxin produced by bacteria during reproduction enters the body along with food, being absorbed in the gastrointestinal tract and acting on the nervous system , causing disturbances in the functioning of cranial nerves , skeletal muscles , and nerve centers of the heart . Ocular symptoms are characteristic (fog, flies in front of the eyes, mydriasis and anisocoria of the pupils , squint ), later bulbar symptoms (impaired speech and swallowing , masked face) join. Death occurs from hypoxia caused by a violation of the metabolic processes of oxygen, asphyxia of the respiratory tract , paralysis of the respiratory muscles and heart muscle .
Physico-chemical indicators
Botulinum toxin has no taste , color or smell (occasionally the affected product takes on the smell of rancid oil). It is destroyed by boiling for 25-30 minutes, by autoclaving for 10 minutes at a temperature of 120 Β° C, when soaking in a solution of 1% baking soda for an hour. The toxin is not destroyed by interaction with pepsin and with hydrochloric acid of gastric juice .
Medical Use
Interest in botulinum toxin as a possible drug appeared at the beginning of the 20th century. During World War II , a comprehensive study of the toxin was conducted for use as a biological weapon . These studies provided the basis for obtaining highly purified crystalline botulinum toxin type A. [3]
The first in medical practice botulinum toxin in the late 70s was used by the American ophthalmologist Alan Scott. He injected purified microdose toxin into the orbital muscle of the eye to treat blepharospasm . He also investigated the effects of toxin on nystagmus , hemifacial spasm , spasmodic torticollis, and spastic leg diseases. [3]
In modern practice, drugs based on botulinum toxin ( Botox , Relatox, Xeomin, BTXA, Dysport, Neuronox) are used to treat hyperactivity of the striated muscles and sphincter muscles, hyperfunction of exocrine glands , and various pain syndromes of a spastic nature. In cosmetology, the toxin is used to smooth facial wrinkles, [3] [4] in a similar way - to stop migraines [5] .
Botulinum toxin combat use
In the 20th century, in preparation for chemical and bacteriological warfare, methods were developed for the production of botulism toxin for military and sabotage purposes. In the USA during the Second World War, botulinum toxin was considered as a promising biological weapon [6] . In the military centers of the USA, England and Canada, it was botulinum toxin type A that was most dangerous for humans [7] . There is a version that botulinum toxin was used in the killing of Reinhard Heydrich by Czechoslovak resistance fighters, who were trained by British intelligence [8] [9] . In 1971, the UN General Assembly approved a convention banning the development, production and stockpiling of toxic weapons and their destruction. Parties to the convention (1985) are 101 states [10] .
As a result of many years of research in 1975, type A botulinum toxin was adopted by the U.S. Army under the XR code, the reserves of which are stored in the Pine Bluff arsenal in Arkansas . Inhalation toxicity for humans LDt 50 20 ng Β· min / l for dry XR and 100 ng Β· min / l for its formulations. Fatal outcome can occur within three days. In air, an aerosol is effective as a biological weapon for 12 hours. Degassing of XR can only be done with aqueous solutions of active chlorine 100-350 mg / l, for example 0.1-0.2% solutions of chloramines or hypochlorites . XR solutions of formaldehyde are especially easily deactivated (toxicity is reduced 100-fold in a minute) [7] .
The biological weapon in the form of an aerosol is the most dangerous for the population, since the toxin is well absorbed from the mucous membranes of the eyes and upper respiratory tract [11] . XR aerosol protection is reliably provided by gas masks and respirators [7] .
Notes
- β Supotnitsky M.V. Chapter 1.5. Toxins of pathogenic bacteria // Microorganisms, toxins and epidemics . - M. , 2000 .-- 376 p.
- β Toxins of Biological Origin . Date of treatment June 19, 2010. Archived on August 25, 2011.
- β 1 2 3 Natalya Astavina. Botulinum toxin. Two sides of the same coin. (Russian) // Consilium provisorum: Journal. - 2009. - No. 2 (58) . - S. 6-9 . Archived June 1, 2010.
- β How to raise eyebrows with Botox: photo before and after, the point of introduction . Eyebrows at Home (December 10, 2018). Date of treatment December 14, 2018.
- β In the United States allowed to treat chronic migraine Botox
- β Creation of bacteriological weapons in the USA . Date of treatment July 23, 2009. Archived April 4, 2012.
- β 1 2 3 V.N. Alexandrov, V.I. Emelyanov. Botulinum toxins and XR substance // Toxins as a chemical weapon (pdf). "Chemistry and Chemists." - the head of the manual βPoisonous substancesβ, M. Voenizdat, 1990 .. Date of treatment July 23, 2010. Archived on April 4, 2012.
- β Defalgue, Ray J., Wright, Amos J. The Puzzling Death of Reinhard Heydrich // Bulletin of Anesthesia History. - January 2009. - T. 27 , no. 1 . - P. 6. Archived on July 20, 2011.
- β W. Seth Carus, Center for Counterproliferation Research, National Defense University. Bioterrorism and biocrimes: the illicit use of biological agents since 1900 . - The Minerva Group, Inc, 2002. - P. 89. - 220 p. - ISBN 9781410100238 .
- β Modern means of defeat (Ppt). Date of treatment July 31, 2009. Archived April 4, 2012.
- β Botulism on eurolab.ua . Date of treatment July 19, 2009. Archived February 1, 2011.
Literature
- V.N. Alexandrov, V.I. Emelyanov. Toxins as a chemical weapon // Poisoning substances / ed. G.A. Sokolsky. - 2nd ed. - M .: Military Publishing House, 1990 .-- 272 p. - 100,000 copies. - ISBN 5-203-00341-6 .