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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1986-6-20
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pubmed:abstractText |
Acetylcholine (ACh) induces a K+ current in rabbit cardiac Purkinje fibres. The question was studied whether ACh produces this effect by modifying the properties of K+ channels pre-existing in the absence of the neurotransmitter or whether it induces the formation of a different type of K+ channels. The relaxation properties of the ACh-induced current and its blockade by Cs+ and Ba2+ have been investigated using voltage clamp. During hyperpolarizing or depolarizing voltage pulses of moderate amplitude, the ACh-induced current is time independent. For large voltage pulses, time-dependent changes of the ACh-induced current are observed. These latter changes can be explained by intracellular K+ accumulation/depletion phenomena or by the effects of ACh on time-dependent currents (e.g. the late outward current, ix). Cs+ and Ba2+ block the ACh-induced current. The block produced by 20 mM-Cs+ is instantaneous and increases with hyperpolarization, i.e. it is voltage dependent. The block produced by Ba2+ at high concentrations (greater than 1 mM) is also instantaneous but complete at all potentials studied, and thus voltage independent. At these concentrations, either ion also blocks the background inward rectifier (iK1) current in a similar way. Low [Ba2+] (less than 0.1 mM) cause a block of the ACh-induced current which is instantaneous and little voltage dependent. The block of iK1 in contrast is time and voltage dependent for the same concentrations. These results indicate that the ACh-induced K+ current is different from the background iK1 current.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-16073434,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-2422347,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-2422349,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-304891,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-308537,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-4541078,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-543757,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-568176,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-569814,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-574635,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6087268,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6273533,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6289255,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6302520,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6310482,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6314245,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6318186,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6323704,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6640861,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-6974340,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-7191986,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-7441543,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-945323,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2422348-988568
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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 |
Feb
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pubmed:issn |
0022-3751
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
371
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
219-37
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:2422348-Acetylcholine,
pubmed-meshheading:2422348-Action Potentials,
pubmed-meshheading:2422348-Animals,
pubmed-meshheading:2422348-Barium,
pubmed-meshheading:2422348-Cesium,
pubmed-meshheading:2422348-Heart Conduction System,
pubmed-meshheading:2422348-Ion Channels,
pubmed-meshheading:2422348-Models, Biological,
pubmed-meshheading:2422348-Potassium,
pubmed-meshheading:2422348-Purkinje Fibers,
pubmed-meshheading:2422348-Rabbits,
pubmed-meshheading:2422348-Time Factors
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pubmed:year |
1986
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pubmed:articleTitle |
Characterization of the acetylcholine-induced potassium current in rabbit cardiac Purkinje fibres.
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pubmed:publicationType |
Journal Article,
In Vitro
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