Difference between revisions of "Toxin" - New World Encyclopedia
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| + | <!-- Unsourced image removed: [[Image:BlackWidowSpider.jpeg|thumb|200px|right|The [[venom]] of the [[black widow spider]] is a potent [[latrotoxin]].]] —> | ||
| + | {{dablink|For a list of biologically injurious substances, including toxins and other materials, as well as their effects, see [[poison]].}} | ||
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| + | A '''toxin''' ([[Greek language|Gk.]] {{polytonic|τοξικόν}} ''toxikon'' "(poison) for use on arrows,") is a [[poison]]ous substance produced by living cells or organisms. Toxins are nearly always [[protein]]s that are capable of causing disease on contact or absorption with [[Biological tissue|body tissue]]s by interacting with biological [[macromolecule]]s such as [[enzyme]]s or [[Receptor (biochemistry)|cellular receptors]]. Toxins vary greatly in their severity, ranging from usually minor and acute (as in a [[bee]] [[Stinger|sting]]) to almost immediately deadly (as in [[botulinum toxin]]). | ||
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| + | Biotoxins vary greatly in purpose and mechanism, and can be highly complex (the [[venom]] of the [[cone snail]] contains dozens of small [[protein]]s, each targeting a specific nerve channel or receptor), or relatively small protein. | ||
| + | |||
| + | ==Use== | ||
| + | Biotoxins in nature have two primary functions: | ||
| + | *Predation ([[spider]], [[snake]], [[scorpion]], [[jellyfish]], [[wasp]]) | ||
| + | *Defense ([[bee]], [[poison dart frog]], [[deadly nightshade]], [[Honey bee|honeybee]], [[wasp]]) | ||
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| + | Some of the more well known types of biotoxins include: | ||
| + | *'''[[Hemotoxin]]s''' target and destroy red blood cells, and are transmitted through the bloodstream. Organisms that possess hemotoxins include: | ||
| + | **[[Pit_viper|Pit Vipers]], such as [[rattlesnake]]s. | ||
| + | *'''[[Necrosis|Necrotoxins]]''' cause necrosis (i.e., death) in the cells they encounter and destroy all types of [[biological tissue|tissue]]. Necrotoxins spread through the bloodstream, but infect all tissues. In humans, [[skin]] and [[muscle]] tissues are most sensitive to necrotoxins. Organisms that possess necrotoxins include: | ||
| + | **The [[Brown recluse spider|brown recluse]] or "fiddle back" spider. | ||
| + | **[[Necrotizing fasciitis]] (the "flesh eating" [[bacteria]]) | ||
| + | *'''[[Neurotoxin]]s''' primarily affect the nervous systems of animals. Organisms that possess neurotoxins include: | ||
| + | **The [[Black widow spider|Black Widow]] and other [[widow spider]]s. | ||
| + | **Most [[scorpion]]s. | ||
| + | **The [[box jellyfish]]. | ||
| + | **[[Elapidae|Elapid]] snakes. | ||
| + | **The [[Cone snail|Cone Snail]]. | ||
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| + | Plant Toxins | ||
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| + | Ricin is found in the castor bean plant. | ||
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| + | ==Non-technical usage== | ||
| + | When used non-technically, the term "toxin" is often applied to any [[toxic]] substances. Toxic substances not of biological origin are more properly termed [[poison]]s. Many non-technical and lifestyle journalists also follow this usage to refer to [[Toxicity (disambiguation)|toxic]] substances in general, though some specialist journalists at publishers such as [[BBC]] and [[The Guardian]] maintain the distinction that toxins are only those produced by living organisms. | ||
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| + | In the context of [[alternative medicine]] the term is often used nonspecifically to refer to any substance claimed to cause ill health, ranging anywhere from trace amounts of pesticides to common food items like refined [[sugar]] or additives like [[artificial sweetener]]s and [[Monosodium glutamate|MSG]].[http://www.curezone.com/diseases/toxins/] These claims are often made without a clear scientific basis or conclusive evidence[http://www.snopes.com/medical/toxins/aspartame.asp], and as such have little to no acceptance in mainstream medicine. | ||
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| + | The term is also used commonly in [[pop psychology]] to describe things that have an adverse effect on psychological health, such as a "toxic relationship," "toxic work environment" or "toxic shame." | ||
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| + | ==See also== | ||
| + | *[[Apitoxin]] | ||
| + | *[[Hemotoxin]] | ||
| + | *[[Mycotoxin]] | ||
| + | *[[Neurotoxin]] | ||
| + | *[[Phototoxin]] | ||
| + | *[[Toxicophore]] | ||
| + | *[[Toxoid]] | ||
| + | *[[Venom]] | ||
| + | *[[List of fictional toxins]] | ||
| + | |||
| + | ==External links== | ||
| + | *[http://www.toxicology.org Society of Toxicology] | ||
| + | *[http://www.jvat.org.br The Journal of Venomous Animals and Toxins including Tropical Diseases] | ||
| + | *[http://plantnet.rbgsyd.gov.au/PlantNet/cycad/toxic.html Cycad toxicity] | ||
| + | *[http://www.guardian.co.uk/corrections/story/0,,1495281,00.html Corrections and clarifications], ''[[The Guardian]]'', [[30 May]], [[2005]]. | ||
| + | |||
| + | [[Category:Toxins| ]] | ||
| + | [[Category:Toxicology]] | ||
| + | {{credit|138184566}} | ||
| + | [[Caregory:Living sciences]] | ||
Revision as of 23:27, 15 June 2007
- For other uses, see Toxin (disambiguation).
- For a list of biologically injurious substances, including toxins and other materials, as well as their effects, see poison.
A toxin (Gk. τοξικόν toxikon "(poison) for use on arrows,") is a poisonous substance produced by living cells or organisms. Toxins are nearly always proteins that are capable of causing disease on contact or absorption with body tissues by interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their severity, ranging from usually minor and acute (as in a bee sting) to almost immediately deadly (as in botulinum toxin).
Biotoxins vary greatly in purpose and mechanism, and can be highly complex (the venom of the cone snail contains dozens of small proteins, each targeting a specific nerve channel or receptor), or relatively small protein.
Use
Biotoxins in nature have two primary functions:
- Predation (spider, snake, scorpion, jellyfish, wasp)
- Defense (bee, poison dart frog, deadly nightshade, honeybee, wasp)
Some of the more well known types of biotoxins include:
- Hemotoxins target and destroy red blood cells, and are transmitted through the bloodstream. Organisms that possess hemotoxins include:
- Pit Vipers, such as rattlesnakes.
- Necrotoxins cause necrosis (i.e., death) in the cells they encounter and destroy all types of tissue. Necrotoxins spread through the bloodstream, but infect all tissues. In humans, skin and muscle tissues are most sensitive to necrotoxins. Organisms that possess necrotoxins include:
- The brown recluse or "fiddle back" spider.
- Necrotizing fasciitis (the "flesh eating" bacteria)
- Neurotoxins primarily affect the nervous systems of animals. Organisms that possess neurotoxins include:
- The Black Widow and other widow spiders.
- Most scorpions.
- The box jellyfish.
- Elapid snakes.
- The Cone Snail.
Plant Toxins
Ricin is found in the castor bean plant.
Non-technical usage
When used non-technically, the term "toxin" is often applied to any toxic substances. Toxic substances not of biological origin are more properly termed poisons. Many non-technical and lifestyle journalists also follow this usage to refer to toxic substances in general, though some specialist journalists at publishers such as BBC and The Guardian maintain the distinction that toxins are only those produced by living organisms.
In the context of alternative medicine the term is often used nonspecifically to refer to any substance claimed to cause ill health, ranging anywhere from trace amounts of pesticides to common food items like refined sugar or additives like artificial sweeteners and MSG.[1] These claims are often made without a clear scientific basis or conclusive evidence[2], and as such have little to no acceptance in mainstream medicine.
The term is also used commonly in pop psychology to describe things that have an adverse effect on psychological health, such as a "toxic relationship," "toxic work environment" or "toxic shame."
See also
- Apitoxin
- Hemotoxin
- Mycotoxin
- Neurotoxin
- Phototoxin
- Toxicophore
- Toxoid
- Venom
- List of fictional toxins
External links
- Society of Toxicology
- The Journal of Venomous Animals and Toxins including Tropical Diseases
- Cycad toxicity
- Corrections and clarifications, The Guardian, 30 May, 2005.
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Caregory:Living sciences
