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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3
|
| pubmed:dateCreated |
1992-9-24
|
| pubmed:abstractText |
1. The effect of 17 beta-oestradiol on cardiac cell contraction, inward Ca2+ current and intracellular free Ca2+ ([free Ca2+]i) was investigated in guinea-pig single, isolated ventricular myocytes. The changes of cell length were measured by use of a photodiode array, the voltage-clamp experiments were performed with a switch clamp system and [free Ca2+]i was measured with the Ca2+ indicator, Fura-2. 2. 17 beta-Oestradiol (10, 30 microM) caused a decrease in cell shortening at both 22 and 35 degrees C. This negative inotropic effect was accompanied by a decrease in action potential duration mainly brought about by a shortening of the plateau region of the action potential. 17 beta-Oestradiol (10, 30 microM) induced a similar decrease in cell shortening in voltage-clamped and current-clamped cells. 3. In Fura-2 loaded cells, 17 beta-oestradiol (10 and 30 microM) decreased systolic Fura-2 fluorescence to 72 +/- 7% and 47 +/- 4% (n = 6, P less than 0.001) of control respectively. 17 beta-Oestradiol (10 microM) had no significant effect on diastolic Fura-2 fluorescence, but at higher concentration (30 microM) induced a slight decrease in resting Fura-2 fluorescence. The effect of 17 beta-oestradiol was reversible after 1-2 min of washout of the steroid. 4. 17 beta-Oestradiol (10 and 30 microM) decreased the peak inward Ca2+ current (ICa), which was sensitive to [Ca2+]o, dihydropyridines and isoprenaline, to 59 +/- 3% and 39 +/- 5% (n = 7 approximately 9, P less than 0.01) respectively, without producing any significant change in the shape of the current-voltage relationship.5. The recovery time of ICa from inactivation was delayed by 17beta-oestradiol (10microM). The inhibitory effect of 17beta-oestradiol on ICa was less at a holding potential of -80 mV than at -40 mV.6. We conclude that 17beta-oestradiol has a negative inotropic effect on guinea-pig single ventricular myocytes by inhibiting ICa and so reducing systolic [Ca2+]i. 17beta-Oestradiol may therefore have a Ca2+ channel blocking property in guinea-pig isolated ventricular myocytes.
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| pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-1822559,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2191782,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2411919,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2437969,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2437970,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2445973,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2448058,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2456513,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2580043,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2580044,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2682207,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-2855642,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-3092754,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-3171468,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-6088117,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-6090637,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-6093100,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-6634382,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-6766222,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1504758-847474
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| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jul
|
| pubmed:issn |
0007-1188
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
106
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
739-45
|
| pubmed:dateRevised |
2010-9-7
|
| pubmed:meshHeading |
pubmed-meshheading:1504758-Action Potentials,
pubmed-meshheading:1504758-Animals,
pubmed-meshheading:1504758-Calcium,
pubmed-meshheading:1504758-Estradiol,
pubmed-meshheading:1504758-Fura-2,
pubmed-meshheading:1504758-Guinea Pigs,
pubmed-meshheading:1504758-Male,
pubmed-meshheading:1504758-Membrane Potentials,
pubmed-meshheading:1504758-Myocardial Contraction,
pubmed-meshheading:1504758-Myocardium
|
| pubmed:year |
1992
|
| pubmed:articleTitle |
Effect of 17 beta-oestradiol on contraction, Ca2+ current and intracellular free Ca2+ in guinea-pig isolated cardiac myocytes.
|
| pubmed:affiliation |
Department of Cardiac Medicine, National Heart and Lung Institute, London.
|
| pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
|