Ingested seafood toxins Flashcards
Ingested seafood toxins - toxins?
- Tetradotoxin
- Ciguatoxin
- Histamine (scombroid poisoning)
Tetradotoxin - source
Pufferfish (Japanese restaurants) –> produced by microorganisms in the fish
Tetradotoxin - action
highly potent toxin –> binds to fast voltage Na+ channels in cardiac/nerve tissues –> prevent depolarization
Tetradotoxin - symptoms
nausea, diarhea, paresthesias, weakness, dizziness, loss of reflexes
overdose –> resp depression + severe hypotension
Tetradotoxin - treatment
primarily supportive
Ciguatoxin - source
Reef fish: such as barracuda, snapper + moray eel
Ciguatoxin - action
openes Na+ channel –> depolarization
Ciguatoxin - symptoms
mimic cholinergic poisoning
Ciguatoxin - treatment
primarily supportive
Histamine (scombroid poisoning) - source
spoiled dark-meat fish suc as tuna, mahi-mahi, mackerel, bonito
Histamine (scombroid poisoning) - action
Bacterial histidine decarbocylase converts histidine to histamine
(Frequently misdiagnosed as fish allergy)
Histamine (scombroid poisoning) - symptoms
mimics anaphylaxis –> may progress to bronchospasm, angioedema, hypotension
Histamine (scombroid poisoning) - treatment
antihistamines –> albuterol + epinephrine if needed
Ingested seafood toxins - review the actions
- Tetradotoxin –> close Na
- Ciguatoxin –> open Na
- Histamine (scombroid poisoning) –> histidine to histamine
Ingested seafood toxins - symptoms
- Tetradotoxin –> GI, paresthesia, loss reflex, resp depression, hypotension
- Ciguatoxin –> miimcs cholinergic poisoning
- Histamine (scombroid poisoning) –> mimics anaphylaxis
