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Epibatidine is a strong toxic alkaloid that is secreted by the frog species ''Epipedobates anthonyi'' (also known as ''Epipedobates tricolor'') which lives in central and southern Ecuador. It was discovered by John W. Daly in 1974; its structure was elucidated in 1992. The toxicity of Epibatidine stems from its ability to bind and turn on nicotinic and muscarinic acetylcholine receptors. These receptors are involved in the transmission of painful sensations, and in movement, among other functions. Epibatidine then causes numbness and eventually paralysis. Doses are lethal when the paralysis causes respiratory arrest. Originally, it was thought that epibatidine could be useful as a drug. However, because it can be deadly even at very low doses, it is no longer being researched for potential therapeutic uses. ==History== Epibatidine was discovered by John W. Daly in the 1970s. It was isolated from the skin of ''Epipdobates anthonyi'' frogs collected by Daly and colleague, Charles Myers. Between 1974 and 1979, Daly and Myers collected the skins of nearly 3000 frogs from various sites in Ecuador, after finding that a small injection of a preparation from their skin caused analgesic (painkilling) symptoms in mice with symptoms that resembled those of an opioid.〔 Despite its common name - Anthony’s Poison Arrow frog - suggesting that it was used by natives when hunting,〔(【引用サイトリンク】title=''Epipedobates anthonyi'' )〕 a paper written by Daly in 2000 claimed that there was no local folklore or folk medicine surrounding the frogs and that they were considered largely unimportant by the locals. The structure of epibatidine was elucidated in 1992, an effort hindered by ''E. anthonyi'' gaining IUCN protected status in 1984.〔 Furthermore, these frogs do not produce the toxin when bred and reared in captivity, because they do not synthesize epibatidine themselves. Like other poison dart frogs, they instead isolate it from their diet and then sequester it on their skin. Likely dietary sources are beetles, ants, mites, and flies. Overcoming the difficulties, the structure was eventually determined, and the first synthesis of epibatidine was completed in 1993. Many other synthesis methods have been developed since.〔 Because of its analgesic effect, there was intense interest in epibatidine’s use as a drug, because it was found not to be an opioid.〔 This meant that it could be used without fear of addiction. However, it was soon found that it cannot be used in humans because the dose resulting in toxic symptoms is too low for it to be safe. 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「epibatidine」の詳細全文を読む スポンサード リンク
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