A high-conductance anion channel in adult amphibian skeletal muscle.
Pflugers Arch
; 410(6): 632-40, 1987 Dec.
Article
em En
| MEDLINE
| ID: mdl-2453021
Membrane patches were excised from enzymatically dissociated frog toe muscle. High-conductance anion channels could be induced in previously quiet patches by 20-120 s depolarizations beyond +20 mV and then studied in the potential range from -80 to +60 mV for a long time. From reversal potentials the estimated permeability ratios PCl/PNa and PCl/Pglucuronate were near 3.5 and 4, respectively. There were probably 5 or more conductance levels (substates) for a single channel, the most common in symmetrical 110 mM NaCl being 260 and 70 pS at 10 degrees C. Gating was complex, with rapid and slow events and several gating modes, including periods of rapid flickering. Channels closed reversibly at potentials more negative than -50 mV. The channel was blocked by application to the cytoplasmic face of tannic acid, gallic acid, and zinc but not of DIDS or 9-anthracene-carboxylic acid, and it was blocked by extracellular zinc.
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Base de dados:
MEDLINE
Assunto principal:
Canais Iônicos
/
Músculos
Idioma:
En
Ano de publicação:
1987
Tipo de documento:
Article