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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
7
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pubmed:dateCreated |
2009-4-7
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pubmed:abstractText |
Ca2+ is known to enter skeletal muscle at rest and during activity. Except for the well-characterized Ca2+ entry through L-type channels, pathways involved in these Ca2+ entries remain elusive in adult muscle. This study investigates Ca2+ influx at rest and during activity using the method of Mn2+ quenching of fura-2 fluorescence on voltage-controlled adult skeletal muscle cells. Resting rate of Mn2+ influx depended on external [Mn2+] and membrane potential. At -80 mV, replacement of Mg2+ by Mn2+ gave rise to an outward current associated with an increase in cell input resistance. Calibration of fura-2 response indicated that Mn2+ influx was too small to be resolved as a macroscopic current. Partial depletion of the sarcoplasmic reticulum induced by a train of action potentials in the presence of cyclopiazonic acid led to a slight increase in resting Mn2+ influx but no change in cell input resistance and membrane potential. Trains of action potentials considerably increased Mn2+ entry through an electrically silent pathway independent of L-type channels, which provided 24% of the global Mn2+ influx at +30 mV under voltage-clamp conditions. Within this context, the nature and the physiological role of the Ca2+ pathways involved during muscle excitation still remain open questions.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-10066910,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-10432347,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-11351027,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-12023224,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-12154184,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-12445457,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-12524279,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-12923063,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-15240463,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-15505226,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-16120606,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-16777939,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-1684042,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-16874448,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-17569733,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-18171728,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-18195089,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-18509671,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-2536366,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-490385,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-6267261,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-8897840,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-9251808,
http://linkedlifedata.com/resource/pubmed/commentcorrection/19348748-9547384
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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 |
Apr
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pubmed:issn |
1542-0086
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pubmed:author |
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pubmed:issnType |
Electronic
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pubmed:day |
8
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pubmed:volume |
96
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2648-57
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pubmed:dateRevised |
2010-9-23
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pubmed:meshHeading |
pubmed-meshheading:19348748-Animals,
pubmed-meshheading:19348748-Cadmium,
pubmed-meshheading:19348748-Calcium,
pubmed-meshheading:19348748-Calcium Channels, L-Type,
pubmed-meshheading:19348748-Calibration,
pubmed-meshheading:19348748-Cations, Divalent,
pubmed-meshheading:19348748-Electric Conductivity,
pubmed-meshheading:19348748-Fura-2,
pubmed-meshheading:19348748-Magnesium,
pubmed-meshheading:19348748-Male,
pubmed-meshheading:19348748-Mice,
pubmed-meshheading:19348748-Muscle Fibers, Skeletal,
pubmed-meshheading:19348748-Sarcolemma,
pubmed-meshheading:19348748-Sarcoplasmic Reticulum
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pubmed:year |
2009
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pubmed:articleTitle |
Electrically silent divalent cation entries in resting and active voltage-controlled muscle fibers.
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pubmed:affiliation |
Physiologie Intégrative Cellulaire et Moléculaire, Université Lyon 1, Centre National de la Recherche Scientifique Unité Mixte de Recherche, 5123 Villeurbanne, France.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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