Effects of the potassium channel blocking dendrotoxins on acetylcholine release and motor nerve terminal activity

A J Anderson, A L Harvey

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

1. The effects of the K+ channel blocking toxins, the dendrotoxins, on neuromuscular transmission and motor nerve terminal activity were assessed on frog cutaneous pectoris, mouse diaphragm and mouse triangularis sterni nerve-muscle preparations. Endplate potentials (e.p.ps) and miniature e.p.ps were recorded with intracellular microelectrodes, and nerve terminal spikes were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. 2. Dendrotoxin from green mamba (Dendroaspis angusticeps) venom and toxin I from black mamba (D. polylepis) venom increased the amplitude of e.p.ps by increasing quantal content, and also induced repetitive e.p.ps. 3. Perineural recordings revealed that dendrotoxins could decrease the component of the waveform associated with K+ currents at the nerve terminals, and induce repetitive activation of nerve terminals. 4. In frog motor nerves, dendrotoxins are known to block the fast f1 component of the K+ current at nodes of Ranvier. Blockade of a similar component of the K+ current at motor nerve terminals may be responsible for the effects of these toxins on neuromuscular transmission. 5. Similar conclusions can be drawn from the results obtained from mouse neuromuscular junctions.
LanguageEnglish
Pages215-221
Number of pages7
JournalBritish Journal of Pharmacology
Volume93
Issue number1
Publication statusPublished - Jan 1988

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Potassium Channels
Acetylcholine
Elapidae
Neuromuscular Junction
Anura
Ranvier's Nodes
Venoms
Microelectrodes
Diaphragm
Electrodes
Skin
dendrotoxin

Keywords

  • acetylcholine
  • animals
  • elapid venoms
  • ion channels
  • male
  • mice
  • inbred BALB C mice
  • motor endplate
  • nerve endings
  • neurotransmitter agents
  • rana pipiens
  • rana temporaria
  • respiratory muscles

Cite this

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abstract = "1. The effects of the K+ channel blocking toxins, the dendrotoxins, on neuromuscular transmission and motor nerve terminal activity were assessed on frog cutaneous pectoris, mouse diaphragm and mouse triangularis sterni nerve-muscle preparations. Endplate potentials (e.p.ps) and miniature e.p.ps were recorded with intracellular microelectrodes, and nerve terminal spikes were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. 2. Dendrotoxin from green mamba (Dendroaspis angusticeps) venom and toxin I from black mamba (D. polylepis) venom increased the amplitude of e.p.ps by increasing quantal content, and also induced repetitive e.p.ps. 3. Perineural recordings revealed that dendrotoxins could decrease the component of the waveform associated with K+ currents at the nerve terminals, and induce repetitive activation of nerve terminals. 4. In frog motor nerves, dendrotoxins are known to block the fast f1 component of the K+ current at nodes of Ranvier. Blockade of a similar component of the K+ current at motor nerve terminals may be responsible for the effects of these toxins on neuromuscular transmission. 5. Similar conclusions can be drawn from the results obtained from mouse neuromuscular junctions.",
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Effects of the potassium channel blocking dendrotoxins on acetylcholine release and motor nerve terminal activity. / Anderson, A J; Harvey, A L.

In: British Journal of Pharmacology, Vol. 93, No. 1, 01.1988, p. 215-221.

Research output: Contribution to journalArticle

TY - JOUR

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N2 - 1. The effects of the K+ channel blocking toxins, the dendrotoxins, on neuromuscular transmission and motor nerve terminal activity were assessed on frog cutaneous pectoris, mouse diaphragm and mouse triangularis sterni nerve-muscle preparations. Endplate potentials (e.p.ps) and miniature e.p.ps were recorded with intracellular microelectrodes, and nerve terminal spikes were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. 2. Dendrotoxin from green mamba (Dendroaspis angusticeps) venom and toxin I from black mamba (D. polylepis) venom increased the amplitude of e.p.ps by increasing quantal content, and also induced repetitive e.p.ps. 3. Perineural recordings revealed that dendrotoxins could decrease the component of the waveform associated with K+ currents at the nerve terminals, and induce repetitive activation of nerve terminals. 4. In frog motor nerves, dendrotoxins are known to block the fast f1 component of the K+ current at nodes of Ranvier. Blockade of a similar component of the K+ current at motor nerve terminals may be responsible for the effects of these toxins on neuromuscular transmission. 5. Similar conclusions can be drawn from the results obtained from mouse neuromuscular junctions.

AB - 1. The effects of the K+ channel blocking toxins, the dendrotoxins, on neuromuscular transmission and motor nerve terminal activity were assessed on frog cutaneous pectoris, mouse diaphragm and mouse triangularis sterni nerve-muscle preparations. Endplate potentials (e.p.ps) and miniature e.p.ps were recorded with intracellular microelectrodes, and nerve terminal spikes were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. 2. Dendrotoxin from green mamba (Dendroaspis angusticeps) venom and toxin I from black mamba (D. polylepis) venom increased the amplitude of e.p.ps by increasing quantal content, and also induced repetitive e.p.ps. 3. Perineural recordings revealed that dendrotoxins could decrease the component of the waveform associated with K+ currents at the nerve terminals, and induce repetitive activation of nerve terminals. 4. In frog motor nerves, dendrotoxins are known to block the fast f1 component of the K+ current at nodes of Ranvier. Blockade of a similar component of the K+ current at motor nerve terminals may be responsible for the effects of these toxins on neuromuscular transmission. 5. Similar conclusions can be drawn from the results obtained from mouse neuromuscular junctions.

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