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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
2
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pubmed:dateCreated |
1994-2-4
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pubmed:abstractText |
Single-channel recordings of a voltage-dependent potassium channel in brown adipocytes of the rat confirm recordings of macroscopic currents. Single-channel conductance (gamma) is 8 pS at 20 degrees C in KF solution inside vs. a modified Ringer's solution outside. With KCl solution outside, gamma is 17 pS for outward currents and 21 pS for inward currents. The majority of the channels inactivate with a time constant around 200 ms; deactivation occurs within milliseconds. The channel is blocked by tetraethylammonium (TEA) with an inhibiting constant of 1.8 mM. The type of block is fast. Selectivity sequence for monovalent cations is K+ > Rb+ >> NH4+ >> Li+ > or = Na+ approximately Cs+. Cs+ at the outside causes a voltage-dependent block of inward currents. This channel is remarkably similar to the delayed rectifier of the F-type in the node of Ranvier. Occasionally, an additional K+ channel was found. This channel is voltage-insensitive, not blocked by 10 mM TEA, and has not been recorded in brown adipocytes before. Physiological relevance of this channel could be the steady-state membrane potential.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0006-3002
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
12
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pubmed:volume |
1153
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
249-56
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8274494-Adipocytes,
pubmed-meshheading:8274494-Adipose Tissue, Brown,
pubmed-meshheading:8274494-Animals,
pubmed-meshheading:8274494-Cations, Monovalent,
pubmed-meshheading:8274494-Cell Membrane,
pubmed-meshheading:8274494-Cells, Cultured,
pubmed-meshheading:8274494-Electric Conductivity,
pubmed-meshheading:8274494-Female,
pubmed-meshheading:8274494-Kinetics,
pubmed-meshheading:8274494-Male,
pubmed-meshheading:8274494-Mathematics,
pubmed-meshheading:8274494-Membrane Potentials,
pubmed-meshheading:8274494-Models, Theoretical,
pubmed-meshheading:8274494-Potassium Channel Blockers,
pubmed-meshheading:8274494-Potassium Channels,
pubmed-meshheading:8274494-Potassium Chloride,
pubmed-meshheading:8274494-Rats,
pubmed-meshheading:8274494-Rats, Sprague-Dawley,
pubmed-meshheading:8274494-Tetraethylammonium,
pubmed-meshheading:8274494-Tetraethylammonium Compounds
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pubmed:year |
1993
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pubmed:articleTitle |
A voltage-dependent and a voltage-independent potassium channel in brown adipocytes of the rat.
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pubmed:affiliation |
Institut für Zoologie, Universität Regensburg, Germany.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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