Source:http://linkedlifedata.com/resource/pubmed/id/16723510
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5
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| pubmed:dateCreated |
2006-10-12
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| pubmed:abstractText |
Decoding of fast cytosolic Ca(2+) concentration ([Ca(2+)](i)) transients by mitochondria was studied in permeabilized cat ventricular myocytes. Mitochondrial [Ca(2+)] ([Ca(2+)](m)) was measured with fluo-3 trapped inside mitochondria after removal of cytosolic indicator by plasma membrane permeabilization with digitonin. Elevation of extramitochondrial [Ca(2+)] ([Ca(2+)](em)) to >0.5 microM resulted in a [Ca(2+)](em)-dependent increase in the rate of mitochondrial Ca(2+) accumulation ([Ca(2+)](em) resulting in half-maximal rate of Ca(2+) accumulation = 4.4 microM) via Ca(2+) uniporter. Ca(2+) uptake was sensitive to the Ca(2+) uniporter blocker ruthenium red and the protonophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone and depended on inorganic phosphate concentration. The rates of [Ca(2+)](m) increase and recovery were dependent on the extramitochondrial [Na(+)] ([Na(+)](em)) due to Ca(2+) extrusion via mitochondrial Na(+)/Ca(2+) exchanger. The maximal rate of Ca(2+) extrusion was observed with [Na(+)](em) in the range of 20-40 mM. Rapid switching (0.25-1 Hz) of [Ca(2+)](em) between 0 and 100 microM simulated rapid beat-to-beat changes in [Ca(2+)](i) (with [Ca(2+)](i) transient duration of 100-500 ms). No [Ca(2+)](m) oscillations were observed, either under conditions of maximal rate of Ca(2+) uptake (100 microM [Ca(2+)](em), 0 [Na(+)](em)) or with maximal rate of Ca(2+) removal (0 [Ca(2+)](em), 40 mM [Na(+)](em)). The slow frequency-dependent increase of [Ca(2+)](m) argues against a rapid transmission of Ca(2+) signals between cytosol and mitochondria on a beat-to-beat basis in the heart. [Ca(2+)](m) changes elicited by continuous or pulsatile exposure to elevated [Ca(2+)](em) showed no difference in mitochondrial Ca(2+) uptake. Thus in cardiac myocytes fast [Ca(2+)](i) transients are integrated by mitochondrial Ca(2+) transport systems, resulting in a frequency-dependent net mitochondrial Ca(2+) accumulation.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Aniline Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Carbonyl Cyanide...,
http://linkedlifedata.com/resource/pubmed/chemical/Fluo-3,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Ruthenium Red,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Xanthenes
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| pubmed:status |
MEDLINE
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| pubmed:month |
Nov
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| pubmed:issn |
0363-6143
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
291
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
C840-50
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| pubmed:dateRevised |
2007-12-3
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| pubmed:meshHeading |
pubmed-meshheading:16723510-Aniline Compounds,
pubmed-meshheading:16723510-Animals,
pubmed-meshheading:16723510-Calcium,
pubmed-meshheading:16723510-Calcium Signaling,
pubmed-meshheading:16723510-Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone,
pubmed-meshheading:16723510-Cats,
pubmed-meshheading:16723510-Cytosol,
pubmed-meshheading:16723510-Female,
pubmed-meshheading:16723510-Heart Ventricles,
pubmed-meshheading:16723510-Kinetics,
pubmed-meshheading:16723510-Male,
pubmed-meshheading:16723510-Mitochondria, Heart,
pubmed-meshheading:16723510-Myocytes, Cardiac,
pubmed-meshheading:16723510-Permeability,
pubmed-meshheading:16723510-Phosphates,
pubmed-meshheading:16723510-Ruthenium Red,
pubmed-meshheading:16723510-Sodium,
pubmed-meshheading:16723510-Xanthenes
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| pubmed:year |
2006
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| pubmed:articleTitle |
Integration of rapid cytosolic Ca2+ signals by mitochondria in cat ventricular myocytes.
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| pubmed:affiliation |
Dept. of Physiology, Loyola University Chicago, Maywood, IL 60153, 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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