Characteristics of membrane channels induced by acetylcholine at frog muscle-tendon junctions.
AUTOR(ES)
Miledi, R
RESUMO
The membrane at the tendinous ends of frog muscle fibres has acetylcholine (ACh) receptors that are blocked by alpha-bungarotoxin. The properties of ACh-activated channels in the myotendinous region were investigated by noise analysis. These channels displayed the same characteristics in normal, denervated and reinnervated muscles. The mean lifetime and conductance of ACh-induced channels at the myotendinous junction resembled those of channels at the normal neuromuscular junction. Both channels opened with a lifetime shorter than that of extrajunctional receptors. Channels of short lifetime could be detected at distances of several hundred micrometres from the tendon junction. The similarity of ACh-activated channels at neuromuscular and myotendon junctions was found both in the fast, 'singly' innervated sartorius and cutaneous pectoris muscle and in the intermediate, multiply innervated submaxillaris muscle.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1199268Documentos Relacionados
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