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dc.contributor.authorBarclay, CJ
dc.contributor.authorWeber, CL
dc.contributor.editorStewart Sage, Jill Berriman (Managing Editor)
dc.date.accessioned2017-05-03T11:42:53Z
dc.date.available2017-05-03T11:42:53Z
dc.date.issued2004
dc.date.modified2007-03-18T21:38:02Z
dc.identifier.issn0022-3751
dc.identifier.doi10.1113/jphysiol.2004.069096
dc.identifier.urihttp://hdl.handle.net/10072/5569
dc.description.abstractThe aim of this study was to determine whether the net efficiency of mammalian muscles depends on muscle fibre type. Experiments were performed in vitro (35é using bundles of muscle fibres from the slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles of the mouse. The contraction protocol consisted of 10 brief contractions, with a cyclic length change in each contraction cycle. Work output and heat production were measured and enthalpy output (work + heat) was used as the index of energy expenditure. Initial efficiency was defined as the ratio of work output to enthalpy output during the first 1 s of activity. Net efficiency was defined as the ratio of the total work produced in all the contractions to the total, suprabasal enthalpy produced in response to the contraction series, i.e. net efficiency incorporates both initial and recovery metabolism. Initial efficiency was greater in soleus (30 ᠱ%; n = 6) than EDL (23 ᠱ%; n = 6) but there was no difference in net efficiency between the two muscles (12.6 ᠰ.7% for soleus and 11.7 ᠰ.5% for EDL). Therefore, more recovery heat was produced per unit of initial energy expenditure in soleus than EDL. The calculated efficiency of oxidative phosphorylation was lower in soleus than EDL. The difference in recovery metabolism between soleus and EDL is unlikely to be due to effects of changes in intracellular pH on the enthalpy change associated with PCr hydrolysis. It is suggested that the functionally important specialization of slow-twitch muscle is its low rate of energy use rather than high efficiency.
dc.description.peerreviewedYes
dc.description.publicationstatusYes
dc.languageEnglish
dc.language.isoeng
dc.publisherBlackwell Publishing Ltd.
dc.publisher.placeUnited Kingdom
dc.publisher.urihttp://www.blackwell-synergy.com/doi/full/10.1113/jphysiol.2004.069096
dc.relation.ispartofpagefrom519
dc.relation.ispartofpageto533
dc.relation.ispartofissue2
dc.relation.ispartofjournalThe Journal of Physiology
dc.relation.ispartofvolume559
dc.subject.fieldofresearchBiological sciences
dc.subject.fieldofresearchBiomedical and clinical sciences
dc.subject.fieldofresearchcode31
dc.subject.fieldofresearchcode32
dc.titleSlow skeletal muscles of the mouse have greater initial efficiency than fast muscles but the same net efficiency
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
gro.facultyGriffith Health, School of Rehabilitation Sciences
gro.rights.copyright© 2004 Blackwell Publishing. The definitive version is available at [www.blackwell-synergy.com.]
gro.date.issued2004
gro.hasfulltextNo Full Text
gro.griffith.authorBarclay, Chris
gro.griffith.authorMinahan, Clare L.


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