ID | 55317 |
フルテキストURL | |
著者 |
Iribe, Gentaro
Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
Kaneko, Toshiyuki
Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
Yamaguchi, Yohei
Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
Naruse, Keiji
Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
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抄録 | The previously reported pressure-volume (PV) relationship in frog hearts shows that end-systolic PV relation (ESPVR) is load dependent, whereas ESPVR in canine hearts is load independent. To study intrinsic cardiac mechanics in detail, it is desirable to study mechanics in a single isolated cardiomyocyte that is free from interstitial connective tissue. Previous single cell mechanics studies used a pair of carbon fibers (CF) attached to the upper surface of opposite cell ends to stretch cells. These studies showed that end-systolic force-length (FL) relation (ESFLR) is load independent. However, the range of applicable mechanical load using the conventional technique is limited because of weak cell-CF attachment. Therefore, the behavior of ESFLR in single cells under physiologically possible conditions of greater load is not yet well known. To cover wider loading range, we contrived a new method to hold cell-ends more firmly using two pairs of CF attached to both upper and bottom surfaces of cells. The new method allowed stretching cells to 2.2 μm or more in end-diastolic sarcomere length. ESFLR virtually behaves in a load independent manner only with end-diastolic sarcomere length less than 1.95 μm. It exhibited clear load dependency with higher preload, especially with low afterload conditions. Instantaneous cellular elastance curves showed that decreasing afterload enhanced relaxation and slowed time to peak elastance, as previously reported. A simulation study of a mathematical model with detailed description of thin filament activation suggested that velocity dependent thin filament inactivation is crucial for the observed load dependent behaviors and previously reported afterload dependent change in Ca(2+) transient shape.
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キーワード | Cell mechanics
Mechano-electric coupling
Modeling
Shortening deactivation
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備考 | 学位審査副論文
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発行日 | 2014-08
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出版物タイトル |
Progress in Biophysics and Molecular Biology
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巻 | 115巻
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号 | 2-3号
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出版者 | Pergamon Press
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開始ページ | 103
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終了ページ | 114
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ISSN | 0079-6107
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NCID | AA00789136
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資料タイプ |
学術雑誌論文
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言語 |
英語
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OAI-PMH Set |
岡山大学
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著作権者 | https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
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論文のバージョン | author
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PubMed ID | |
DOI | |
Web of Science KeyUT | |
関連URL | https://doi.org/10.1016/j.pbiomolbio.2014.06.005
http://ousar.lib.okayama-u.ac.jp/55243
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