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A toxin (from ) is a poisonous substance produced within living cells or organisms;〔(【引用サイトリンク】title=toxin - Definition from the Merriam-Webster Online Dictionary )〕 synthetic toxicants created by artificial processes are thus excluded. The term was first used by organic chemist Ludwig Brieger (1849–1919).〔http://books.google.co.za/books?id=oWhqhK1cE-gC&pg=PA6&lpg=PA6&dq=Ludwig+Brieger+()&source=bl&ots=7fa0fkkgkV&sig=ItABIJkoSsxyTdM9ts3iSSD3NQc&hl=en&ei=2lwmTKuaH4i6jAffyMGUAQ&sa=X&oi=book_result&ct=result&resnum=4&ved=0CCMQ6AEwAw#v=onepage&q=Ludwig%20Brieger%20()&f=false〕 Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their severity, ranging from usually minor (such as a bee sting) to almost immediately deadly (such as botulinum toxin). ==Terminology== Toxins are often distinguished from other chemical agents by their method of production—the word toxin does not specify method of delivery (compare with venom and the narrower meaning of poison—all substances that can also cause disturbances to organisms). It simply means it is a biologically produced poison. There was an ongoing terminological dispute between NATO and the Warsaw Pact over whether to call a toxin a biological or chemical agent, in which the NATO opted for biological agent, and the Warsaw Pact, like most other countries in the world, for chemical agent. According to an International Committee of the Red Cross review of the Biological Weapons Convention, "Toxins are poisonous products of organisms; unlike biological agents, they are inanimate and not capable of reproducing themselves", and "Since the signing of the Convention, there have been no disputes among the parties regarding the definition of biological agents or toxins".〔(【引用サイトリンク】title=The Biological Weapons Convention - An overview )〕 According to Title 18 of the United States Code, "... the term "toxin" means the toxic material or product of plants, animals, microorganisms (including, but not limited to, bacteria, viruses, fungi, rickettsiae or protozoa), or infectious substances, or a recombinant or synthesized molecule, whatever their origin and method of production..."〔(【引用サイトリンク】title=U.S. Code )〕 A rather informal terminology of individual toxins relates them to the anatomical location where their effects are most notable: * Hemotoxin, causes destruction of red blood cells (hemolysis) * Phototoxin, causes dangerous photosensitivity On a broader scale, toxins may be classified as either exotoxins, being excreted by an organism, or endotoxins, that are released mainly when bacteria are lysed. Related terms are: * Toxoid, weakened or suppressed toxin * Venom, toxins in the sense of use by certain types of animals 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「toxin」の詳細全文を読む スポンサード リンク
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