dc.contributor.author |
Garrett, Amy S |
|
dc.contributor.author |
Loiselle, Denis S |
|
dc.contributor.author |
Han, JuneChiew |
|
dc.contributor.author |
Taberner, Andrew J |
|
dc.coverage.spatial |
England |
|
dc.date.accessioned |
2021-11-11T04:44:50Z |
|
dc.date.available |
2021-11-11T04:44:50Z |
|
dc.date.issued |
2021-10-3 |
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dc.identifier.citation |
Experimental physiology 106(12):2445-2456 Dec 2021 |
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dc.identifier.issn |
0958-0670 |
|
dc.identifier.uri |
https://hdl.handle.net/2292/57383 |
|
dc.description.abstract |
<h4>New findings</h4>What is the central question of this study? Intracellular energetic processes in quiescent cardiac muscle release 'basal' heat; during contraction, a much larger amount of 'active' heat is also produced. Measurement challenges have previously constrained researchers to assume that basal heat rate remains constant during contraction and shortening. Is this assumption correct? What is the main finding and its importance? Our results overturn convention: basal heat rate is modulated by the extent and velocity of muscle shortening. Their relative contributions are muscle-specific. We apply a method with which researchers can now disentangle, during each experiment, changes in basal heat from active heat production, providing more precise measures of the individual energetic processes underlying cardiac muscle contraction.<h4>Abstract</h4>Separating the variations in cardiac basal heat rate from variations in active heat rate is necessary to accurately determine cardiac muscle energy consumption during the performance of active work. By developing a model of cardiac muscle basal heat rate, we aim to investigate changes in basal heat rate when cardiac muscle performs work. Experiments were conducted on ten isolated rat cardiac trabeculae subjected to both active (work-loops) and quiescent (length-change and velocity) interventions. Muscle force, length and heat rate output were simultaneously measured in a flow-through work-loop calorimeter. Quiescent muscle characteristics were utilized to parameterize muscle-specific models of change in basal heat rate, and thereby to predict dynamic changes in basal heat rate during active work-loop contraction. Our data show that the quiescent heat characteristics of cardiac muscle varied between samples, displaying dependence on both the extent and the rate of muscle length change. We found a moderate correlation between muscle dimensions (cross-sectional area and volume) and the length-dependent basal heat parameter (p-value = 0.0330 and p-value = 0.0242, respectively), but no correlation with the velocity-dependent parameter. These findings lead us to conclude that the heat output of cardiac muscle at quiescence varies, with both extent and velocity of shortening, to an extent that is muscle-specific, and that this variation must be measured, and accounted for, in each specimen, when assessing active energetics. This article is protected by copyright. All rights reserved. |
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dc.format.medium |
Print-Electronic |
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dc.language |
eng |
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dc.publisher |
Wiley |
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dc.relation.ispartofseries |
Experimental physiology |
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dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
|
dc.rights |
This is the peer reviewed version of the following article:Experimental physiology 106(12):2445-2456 Dec 2021, which has been published in final form at http://doi.org/10.1113/ep089800 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. |
|
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
|
dc.rights.uri |
https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html |
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dc.subject |
cardiac basal heat |
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dc.subject |
cardiac heat modelling |
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dc.subject |
cardiac muscle energetics |
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dc.subject |
feng effect |
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dc.subject |
heart muscle |
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dc.subject |
resting heat |
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dc.subject |
0606 Physiology |
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dc.subject |
1106 Human Movement and Sports Sciences |
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dc.subject |
1116 Medical Physiology |
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dc.title |
Heat production in quiescent cardiac muscle is length-, velocity-, and muscle-dependent: Implications for active heat measurement. |
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dc.type |
Journal Article |
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dc.identifier.doi |
10.1113/ep089800 |
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dc.date.updated |
2021-10-26T01:52:57Z |
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dc.rights.holder |
Copyright: The author |
en |
pubs.author-url |
https://www.ncbi.nlm.nih.gov/pubmed/34605075 |
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pubs.publication-status |
Published |
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dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
pubs.subtype |
Journal Article |
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pubs.elements-id |
869637 |
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dc.identifier.eissn |
1469-445X |
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pubs.online-publication-date |
2021-10-3 |
|