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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
8
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pubmed:dateCreated |
2009-2-25
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pubmed:abstractText |
The physiological significance of the cardiac glycoside-binding site on the Na,K-ATPase remains incompletely understood. This study used a gene-targeted mouse (alpha2(R/R)) which expresses a ouabain-insensitive alpha2 isoform of the Na,K-ATPase to investigate whether the cardiac glycoside-binding site plays any physiological role in active Na(+)/K(+) transport in skeletal muscles or in exercise performance. Skeletal muscles express the Na,K-ATPase alpha2 isoform at high abundance and regulate its transport over a wide dynamic range under control of muscle activity. Na,K-ATPase active transport in the isolated extensor digitorum longus (EDL) muscle of alpha2(R/R) mice was lower at rest and significantly enhanced after muscle contraction, compared with WT. During the first 60 s after a 30-s contraction, the EDL of alpha2(R/R) mice transported 70.0 nmol/g.min more (86)Rb than WT. Acute sequestration of endogenous ligand(s) in WT mice infused with Digibind to sequester endogenous cardiac glycoside(s) produced similar effects on both resting and contraction-induced (86)Rb transport. Additionally, the alpha2(R/R) mice exhibit an enhanced ability to perform physical exercise, showing a 2.1- to 2.8-fold lower failure rate than WT within minutes of the onset of moderate-intensity treadmill running. Their enhanced exercise performance is consistent with their enhanced contraction-induced Na,K-ATPase transport in the skeletal muscles. These results demonstrate that the Na,K-ATPase alpha2 isozyme in skeletal muscle is regulated dynamically by a mechanism that utilizes the cardiac glycoside-binding site and an endogenous ligand(s) and that its cardiac glycoside-binding site can play a physiological role in the dynamic adaptations to exercise.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-11171381,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-11438691,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-12045105,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-12397396,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-12763894,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-14506306,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-14559919,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-15542571,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-15837822,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-16051601,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-16243970,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-16529550,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-17610345,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-18174214,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-18555269,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-2443689,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-2558169,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-2853965,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-3009961,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-3714446,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-4080711,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-479825,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-6292738,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-6304285,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-7191989,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-7932768,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-7945198,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-8178965,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-8729682,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-9379412,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-943782,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19196986-9529622
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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 |
1091-6490
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pubmed:author |
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pubmed:issnType |
Electronic
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pubmed:day |
24
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pubmed:volume |
106
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2565-70
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:19196986-Animals,
pubmed-meshheading:19196986-Binding Sites,
pubmed-meshheading:19196986-Biological Transport, Active,
pubmed-meshheading:19196986-Cardiac Glycosides,
pubmed-meshheading:19196986-Isoenzymes,
pubmed-meshheading:19196986-Mice,
pubmed-meshheading:19196986-Muscle, Skeletal,
pubmed-meshheading:19196986-Physical Conditioning, Animal,
pubmed-meshheading:19196986-Sodium-Potassium-Exchanging ATPase
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pubmed:year |
2009
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pubmed:articleTitle |
The cardiac glycoside binding site on the Na,K-ATPase alpha2 isoform plays a role in the dynamic regulation of active transport in skeletal muscle.
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pubmed:affiliation |
Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0576, USA.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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