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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
4
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pubmed:dateCreated |
1995-7-24
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pubmed:abstractText |
Fluorescent Ca indicators have been extremely valuable in understanding intracellular [Ca] ([Ca]i) regulation in many cell types. The calibration of these indicators in the intracellular environment, however, has been a continuous challenge. We performed in vivo calibrations of indo-1 in isolated rabbit ventricular myocytes loaded with the acetoxymethylester form of indo-1 and used the perforated patch variation of whole cell voltage clamp. Voltage, [Na], and [K] gradients were eliminated to approach equilibrium. We also took advantage of the powerful Na/Ca exchange in cardiac myocytes so that [Ca]i would be equilibrated with [Ca]o (because there was no [Na] or voltage gradient). The equilibration of [Na] and [Ca] across the membrane was tested by measuring the reversal potential of Na current and poking the cell to test for changes in [Ca]i-dependent fluorescence ratio. The apparent dissociation constant, Kd for indo-1 in the cellular environment was 844 nM, which is approximately 2-3 times higher than that in aqueous solutions. In a separate series of experiments, a null point approach was used to determine the [Ca]i in intact cells at rest for very long periods (82 +/- 6 nM). This is lower than that measured 15 s after a train of steady-state twitches ([Ca]i = 294 +/- 53 nM). These experiments also allowed the direct assessment of the shortening versus [Ca]i relationship in intact cells.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-1288134,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-1420876,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-1464847,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-1783896,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-1884395,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-1928394,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2015620,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2275965,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2309919,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2333986,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2419483,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2459299,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2537030,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2621609,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-2782386,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-3266079,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-3719928,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-3838314,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-8014906,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-8046643,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-8067437,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-8118949,
http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-8201981,
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http://linkedlifedata.com/resource/pubmed/commentcorrection/7787031-8387590
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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 |
0006-3495
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
68
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1453-60
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:7787031-Animals,
pubmed-meshheading:7787031-Biophysical Phenomena,
pubmed-meshheading:7787031-Biophysics,
pubmed-meshheading:7787031-Calcium,
pubmed-meshheading:7787031-Fluorescent Dyes,
pubmed-meshheading:7787031-Indoles,
pubmed-meshheading:7787031-Intracellular Fluid,
pubmed-meshheading:7787031-Kinetics,
pubmed-meshheading:7787031-Male,
pubmed-meshheading:7787031-Myocardial Contraction,
pubmed-meshheading:7787031-Myocardium,
pubmed-meshheading:7787031-Rabbits
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pubmed:year |
1995
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pubmed:articleTitle |
Calibration of indo-1 and resting intracellular [Ca]i in intact rabbit cardiac myocytes.
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pubmed:affiliation |
Department of Physiology, Loyola University School of Medicine, Maywood, Illinois 60153, USA.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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