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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4
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pubmed:dateCreated |
1990-10-18
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pubmed:abstractText |
The effects of chloramine-T (CL-T) on voltage-dependent potassium channels in neuroblastoma cells were analysed using the whole-cell current recording technique. CL-T irreversibly decreased the peak whole-cell K current, considerably slowed its inactivation and shifted its activation-voltage curve towards positive voltages by 6 mV. Under control conditions, the inactivation of the whole-cell K current could be described by the sum of two exponentials, F and S, whose time constants at +50 mV were tau F = 1.00 +/- 0.15 S and tau S = 5.72 +/- 0.47 S respectively. After CL-T, it could be described by the sum of two (S1 and S2) or three (F, S1 and S2) exponentials whose time constants at +50 mV were: tau F = 0.81 +/- 0.22 S, tau S1 = 6.46 +/- 0.60 S and tau S2 = 48.56 +/- 3.64 S. Under control conditions, F and S inactivating components of the whole-cell K current were blocked by 4-aminopyridine, with a Hill coefficient of 1 and apparent dissociation constants of 0.04 and 0.7 mM respectively. After CL-T, both S1 and S2 components were equally blocked by 4-aminopyridine with a Hill coefficient of 0.25, being reduced to 64% of their control values by 10 mM. CL-T is known to slow the inactivation of sodium channels and to oxidize sulphydryl amino acids and unsaturated lipids. It is concluded that the inactivation gates of voltage-dependent sodium and potassium channels are either constituted of the same amino acid residues or are controlled by unsaturated lipid surrounding or bound to the channel proteins.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/4-Aminopyridine,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Chloramines,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0031-6768
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
416
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
393-7
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2169042-4-Aminopyridine,
pubmed-meshheading:2169042-Animals,
pubmed-meshheading:2169042-Calcium Channels,
pubmed-meshheading:2169042-Chloramines,
pubmed-meshheading:2169042-Electrophysiology,
pubmed-meshheading:2169042-Glioma,
pubmed-meshheading:2169042-Hybrid Cells,
pubmed-meshheading:2169042-Ion Channel Gating,
pubmed-meshheading:2169042-Neuroblastoma,
pubmed-meshheading:2169042-Potassium,
pubmed-meshheading:2169042-Potassium Channels,
pubmed-meshheading:2169042-Tumor Cells, Cultured
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pubmed:year |
1990
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pubmed:articleTitle |
Modification of electrophysiological and pharmacological properties of K channels in neuroblastoma cells induced by the oxidant chloramine-T.
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pubmed:affiliation |
Laboratoire de Physiologie Comparée, URA CNRS 1121, Université Paris-Sud, Orsay, France.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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