Enhancement by Anemonia sulcata toxin II of spontaneous quantal transmitter release from mammalian motor nerve terminals.

The action of Anemonia sulcata toxin II (ATX-II) on spontaneous quantal transmitter release from motor nerve terminals was investigated by recording miniature end-plate potentials (MEPPs) from isolated mouse phrenic nerve--hemidiaphragm nerve--muscle preparations. ATX-II (3.2 microM) when applied for 3-40 min to junctions bathed in a normal ionic medium enhanced about one hundred fold the rate of spontaneous MEPPs.

[Effects of a neurotoxin isolated from the sea anemone, Anemonia sulcata, at frog neuromuscular junction (author's transl)].

ATX II is a toxin extracted from tentacles of Anemonia sulcata. It was known that this protein displays neurotoxic effects on frog isolated neuromuscular preparation (Fig. 1, 2) and that muscular contractures observed with ATX II are blocked by d-tubocurarine (Fig.

[Comparative action of toxins isolated from the venom of the scorpion (Androctonus australis) and the tentacles of the sea anemone (Anemonia Sulcata) on an isolated frog neuromuscular preparation].

We have shown that, if Scorpion venom is acting a skeletal muscle indirectly by releasing Acetycholine and directly by inducing an increase in intracellular free calcium, the main action of toxin II isolated from Anemonia Sulcata tentacles is presynaptic.