omega-Conotoxin GVIA binds to and blocks rat neuromuscular junction.
The effect of omega-conotoxin GVIA, a specific blocker of N-type calcium channels, on the synaptic transmission at the mammalian neuromuscular junction is controversial. We have found that 125I-omega-conotoxin binds to rat tibialis muscle end-plate; that omega-conotoxin blocks the neuromuscular transmission both in vivo, in the sciatic nerve-tibialis anterior muscle, and in vitro in the isolated phrenic nerve-diaphragm preparation; and does not affect muscle nicotinic receptors. We conclude that in rat neuromuscular junctions N-type calcium channels are important for neurotransmitter secretion.
Department of Pharmacology, University of Milan, Italy.
G
G
Rossoni
F
F
Berti
L
L
La Maestra
F
F
Clementi
D000818:Animals; D002121:Calcium Channel Blockers / Q000378:metabolism* / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism* / Q000494:pharmacology*; D051381:Rats; D012584:Sciatic Nerve / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects; D020866:omega-Conotoxin GVIA
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D009466:Neuromuscular Blocking Agents; D010455:Peptides; D020866:omega-Conotoxin GVIA