Properties: A small, heterocyclic,
organic, water-soluble non-protein
molecule that is heat-stable (except in
Background: Poisoning with the potent marine neurotoxin
tetrodotoxin (TTX) occurs after ingestion of various species of puffer fish
(i.e. Takifugu or ‘fugu’ in Japanese) as well as a number of other animals. Sushi chefs
who wish to prepare fugu, considered a delicacy in Japan, must be specially
trained and certified by the Japanese government, in order to prepare the flesh
free of the liver, gonads and skin - where the toxin is concentrated. As
toxicity levels are seasonal, fugu is prepared from October to March. However,
many cases of TTX poisoning are reported each year in Japan due to patients ingesting fugu.
Toxicity: Toxicity levels are unclear as puffer fish have
different concentrations of TTX. The LD50 for a mouse is around 10 ng. But a
dose of 1-2 mg of pure TTX may be lethal to humans (LD50 is 5.0 - 8.0 µg/kg). A single milligram or less of TTX - an quantity that
can be placed on a pinhead, is enough to kill a human adult.
Pathophysiology: A bacterial or dinoflagellate species in endosymbiosis with the puffer fish is believed to synthesis TTX.
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