[The action of the venom of the spider Eresus niger on the neuromuscular synapses of the frog]. / Deistvie iada pauka Eresmus niger na nervno-myshechnye sinapsy liagushki.

The effect of Eresus niger spider venom on frog neuromuscular preparations has been studied using the intracellular microelectrodes. The spider venom has been found to block both spontaneous and elicited transmitter release and possesses the phospholipase activity. It has been suggested that the venom blocking synaptic transmission results from its phospholipase activity by analogy with the action of snake presynaptic neurotoxins.

[Channel-forming action--a general property of venoms of spiders in the family Theridiidae (Aranei)]. / Kanaloobrazuiushchee deistvie--obshchee svoistvo iadov paukov semeistva Theridiidae (Aranei).

The study of venom action of 10 spider species of Theridiidae family has shown that they cause the formation of the cation selective channels on the bilayer lipid membranes. This action does not depend on the species sex and age and it is the important diagnostic characteristic of the family. The channel-forming effect is due to the presence of the peptide with molecular weight about 5000 daltons in venoms of Theridiidae spider family.

Postsynaptic blocking of glutamatergic and cholinergic synapses as a common property of Araneidae spider venoms.

Venom effects of eight Araneidae spider species were studied using locust and frog neuromuscular junctions. The spider venoms irreversibly blocked miniature excitatory postsynaptic potentials and excitatory postsynaptic potentials of locust neuromuscular junction. The frog miniature end-plate potentials and end-plate potentials were also blocked, but they recovered upon washing of the preparation with physiological solution.