toxicity and toxicology

Tetrodoptoxin in short

Scroll down the page to read the summary table on tetradotoxin (TTX)

TTX	Tetrodotoxin also known as tetrodox, is a very powerful neurotoxin synthesized from puffer fish and some newts, small polyps, angel fishes, Atelopus toads, starfish, cod and some bacterial and viral species
TTX: year of its discovery	1909: TTX was first isolated from a Japanese scientist 1964: study of the mechanism of action of TTX
TTX and Japan	In Japanese restaurants, puffer fish is a treat. Some like to perceive numbness of the lips or tongue by eating a small fragment of puffer liver containing the deadly toxin → there have been cases of accidental death
TTX and puffer fish	The TTX is contained in the liver and in the ovary of the puffer fish, while in the meat the quantity of TTX is almost nothing or scarce → to consume the puffer fish it is essential to remove the organs containing the TTX
TTX and cyanide	TTX is considered even more dangerous than cyanide (100 times more toxic than potassium cyanide)
TTX and mechanism of action	Ingestion of 1 milligram of TTX: Strong bond between TTX and voltage-dependent sodium channel The bond remains for 10 seconds Sodium is not able to enter the canal The membrane action is abruptly interrupted Death due to respiratory failure and paralysis of the diaphragm
TTX: lethal dose	LD50 of TTX in the mouse: 334 μg per kg LD50 of TTX in humans: 25 mg for a subject of 75 kg per os LD50 of TTX in humans: 8 μg per kg intravenously
TTX poisoning	Onset : slight numbness of the tongue and lips, paresis to the face and lower extremities, dizziness, shortness of breath, tinnitus, irregular heartbeat, nausea, diarrhea and vomiting Symptomatic aggravation : movement disorders and breathing difficulties, the patient appears pale, shows a marked hypotension and difficulty in expressing himself Final stage : the paralysis becomes more and more marked, the subject shows convulsions, cardiac arrhythmia and mental imbalances of varying degrees Death arises after 20 minutes / 8 hours from the ingestion of poisoned meat: sometimes, the patient remains conscious until a few moments before he dies
TTX poisoning: epidemiology	From 1974 until 1983: 646 cases of poisoning with 179 victims Currently: 200 cases of poisoning per year, with a mortality of around 50%
Zombising practice in Haiti	Zombie powder is used in voodoo rituals, in order to reduce the adepts into a trance state
TTX poisoning: therapies	No truly effective antidote was designed Immediate gastric lavage is indispensable Administration of molecules able to bind the toxin (activated carbon) In case of hypotension → administration of pharmacological substances alpha-adrenergic agonists in saline intravenously Artificial respiration and breath monitoring Cardiac massage and heart rate monitoring In the event of severity, assisted ventilation