Abstract
Spider venoms are proving to be important sources of specific ion channel toxins. Venom of Agelenopsis aperta, a funnel web spider, contains a class of polypeptide toxins which blocks neuromuscular synapses at nanomolar concentrations. Detailed physiological analyses of block caused by one of these toxins, omega-Aga-I, show that it suppresses transmitter release at insect and frog neuromuscular junctions and blocks calcium spikes in insect neuronal cell bodies. omega-Aga-I may define a binding site on neuronal calcium channels which is common to both vertebrates and invertebrates.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Agatoxins
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Animals
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Arthropod Venoms / pharmacology*
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Calcium / pharmacology
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Calcium Channel Blockers / pharmacology*
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Evoked Potentials / drug effects
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Grasshoppers
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Houseflies
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In Vitro Techniques
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Neuromuscular Junction / drug effects
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Neuromuscular Junction / physiology
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Neurons / drug effects
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Neurons / physiology
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Rana pipiens
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Spider Venoms / isolation & purification
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Spider Venoms / pharmacology*
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Synapses / drug effects
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Synapses / physiology
Substances
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Agatoxins
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Arthropod Venoms
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Calcium Channel Blockers
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Spider Venoms
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omega-agatoxin I
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Calcium