The neurotoxin responsible for the paralysis seen in puffer fish (Fugu) poisoning is tetrodotoxin. Its mechanism of action is MOST similar to which of the following forensic poisons?
- A Aconitine from Aconitum napellus
- B Saxitoxin from red tide dinoflagellates ✓
- C Batrachotoxin from poison dart frogs
- D Palytoxin from Palythoa coral
Correct answer: B. Saxitoxin from red tide dinoflagellates
Explanation
Tetrodotoxin (TTX) and saxitoxin (STX, responsible for paralytic shellfish poisoning) both act by blocking the outer pore of voltage-gated sodium channels from the extracellular side, preventing sodium influx and therefore preventing action potential generation. This leads to ascending flaccid paralysis and respiratory failure. Aconitine and batrachotoxin have the opposite effect — they keep sodium channels permanently open. Palytoxin affects the sodium-potassium ATPase by a distinct mechanism.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.