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. 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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