[Release of 14C-acetylcholine from synaptosomes as affected by presynaptic neurotoxins from bee and cobra venoms--phospholipases A2].

The effect of presynaptic neurotoxin from bee and cobra venom--phospholipases A2 on Na+-dependent high affinity [14C]choline transport from the striate body of rat brain into synaptosomes has been studied. It was shown that both phospholipases A2 inhibit the re-uptake of [14C]choline and specifically stimulate the release of [14C]acetylcholine from the synaptosomes. This effect is especially well-pronounced for bee venom phospholipase A2. It was assumed that damages of biochemical processes on the presynaptic membrane result in a blockade of synaptic transmission in nerve-muscle preparations.