Effects of sea anemone (Heteractis magnifica and Actinia equina) cytolysins on synaptosomal uptake of GABA and choline.

Magnificalysin I and II (HMg I and II) and equinatoxin II (EqTx II) are cytolytic toxins extracted from sea anemones Heteractis magnifica and Actinia equina, respectively. They induced haemolysis in rat red blood cells and inhibited gamma amino butyric acid (GABA) and choline uptake into rat brain synaptosomes. These effects were concentration dependent. The inhibition of GABA and choline uptake could be overcome by the addition of exogenous sphingomyelin, suggesting that there might be interaction between these cytolysins and the phospholipid. Although the precise mechanisms involved in haemolysis and inhibition of GABA and choline uptake are unknown, they appeared to be different.