A novel peptide toxin from Trimeresurus wagleri acts pre- and post-synaptically to block transmission at the rat neuromuscular junction
| Autor: | Simon P. Aiken, Joseph J. McArdle, Scott A. Weinstein, James J. Schmidt, Lawrence C. Sellin |
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| Rok vydání: | 1992 |
| Předmět: |
Male
medicine.medical_specialty Health Toxicology and Mutagenesis Neuromuscular transmission Neuromuscular Junction Peptide Venom Biology Toxicology medicine.disease_cause Motor Endplate Synaptic Transmission Neuromuscular junction Membrane Potentials Extensor digitorum longus muscle chemistry.chemical_compound Internal medicine Crotalid Venoms medicine Animals Neurotransmitter Uptake Inhibitors Rats Wistar Neurotransmitter Evoked Potentials Toxins Biological Pharmacology chemistry.chemical_classification Neurotransmitter Agents Toxin Rats Electrophysiology medicine.anatomical_structure Endocrinology chemistry Synapses Quantum Theory Neuromuscular Blocking Agents Peptides |
| Zdroj: | Pharmacologytoxicology. 70(6 Pt 1) |
| ISSN: | 0901-9928 |
| Popis: | The neuromuscular effects of a peptide toxin (peptide I) from venom of Trimeresurus wagleri were investigated using the rat extensor digitorum longus muscle/peroneal nerve preparation. Sub-micromolar concentrations depressed endplate currents (EPCs) produced in response to nerve stimulation. Since quantal content of EPCs was not altered, it appears that the site of action is post-synaptic. However, higher concentrations (1.4-2.9 microM) also inhibited spontaneous release of transmitter. Nerve stimulation in the presence of peptide I caused 'rundown' of EPC amplitude, evidence that the peptide acts pre-synaptically to interfere with transmitter release. Recovery from this effect occurred within 3-5 min. of washing, but EPC amplitude took 20-30 min. to recover. The dual action of this peptide makes it unusual amongst naturally-occurring toxins, and these data suggest that further investigation of the peptide (and its analogues) could yield new information about neurotransmitter release. |
| Databáze: | OpenAIRE |
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