Isolation of toxins from Buthus occitanus sp. scorpion and their action on excitability of myelinated nerve.

A series of short neurotoxins (molecular weight 3500-5000 D) was isolated from Vietnamese scorpion B. occitanus sp. All these toxins blocked generation of action potentials (this effect depended on their molecular weight), but did not change conduction velocity and excitation threshold of the nerve.