ABSTRACT
The Argiope lobata venom is shown to block synaptic potential at locust neuromuscular junctions and inhibit the high-affinity sodium independent L[3H]glutamate binding site in locust muscle membranes. The data obtained due to fractionation of venom evidence that it contains components which block synaptic potential and inhibit the binding of L[3H]glutamate (5 kDa and more) as well as components which block synaptic potential but do not inhibit the binding of L[3H]glutamate less than 5 kDa. These observations indicate that spider venom contains at least two components with different mechanism of action.
Subject(s)
Arthropod Venoms/pharmacology , Glutamates/metabolism , Neuromuscular Junction/metabolism , Spider Venoms/pharmacology , Animals , Binding, Competitive , Glutamic Acid , Grasshoppers , In Vitro Techniques , Molecular Weight , Neuromuscular Junction/drug effects , Spider Venoms/isolation & purificationABSTRACT
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.