BIOL 3P34 Lecture Notes - Lecture 10: Saxitoxin, Peptide, Choline
7 Nov 2016
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Document Summary
Saxitoxin (stx) is not destroyed by heat (cooking) if people get on a respirator quickly enough they might survive. Also acts on voltage gated na+ channels. Produced by marine dinoflagellates (unicellular photosynthetic protists) Some are luminous and contribute to the twinkling or flashing effects seen at night especially in the tropics. Also produce the poisonous and destructive red tides. Potentially fatal syndrome associated with consumption of shellfish that have accumulated saxitoxin. A single clam (cooked or uncooked) can prove fatal. Symptoms: numbness, tingling, uncoordinated movements, nausea, incoherent speech if you block the na+ channels with ttx or. Stx you only record the outward k+ current. Blocks k+ channels and only shows na+ current. Used in mm quantities on the inside of a squid giant axon, also eff ective on the outside in some preps (eg. a frog nerve) Sometimes it will act on the inside sometimes on the outside.
