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GLOSSARY
Analgesic: Tetrodotoxin
Tetrodotoxin is refined from the highly toxic ovaries of various species of blowfish (genus Mafugu), notably torafugn (Tetraodon rubripes) and mafugu.In 1913, the poison in refined form was found to be effective as an analgesic for specific conditions such as neuralgia and rheumatism. In 1952, a research team headed by Kawamura Masaaki of the Sankyo Company developed a technique for mass-production of tetrodotoxin in crystalline form: ten grams can be refined from about one ton of blowfish ovaries.
Tetrodotoxin has been analyzed by many Japanese pharmacologists including Fukuda Tokushi of Kyushu University. Its effects are rapid and wide-spread:vomiting; paralysis, Iowered blood pressure, arrhythmia, reduction of stomach secretion and anti-diuresis. Recently, it has been established that tetrodotoxin has a unique effect on the transmission of nerve impulses. A tetrodotoxin solution of extremely low strength blocks the entry of sodium ions into nerve membrane without effecting the permeation of chlorine and potassium ions. This characteristic of tetrodotoxin is considered to have great therapeutic potential.
In Japan the flesh of fugu is considered to be a delicacy and it is eaten both raw and cooked. Although the toxic parts of the fish are carefully removed before eating, fatal cases of tetrodotoxin poisoning occur from time to time.