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dc.contributor.authorBarclay, Chrisen_US
dc.contributor.authorMinahan, Clareen_US
dc.contributor.editorStewart Sage, Jill Berriman (Managing Editor)en_US
dc.date.accessioned2017-05-03T11:42:53Z
dc.date.available2017-05-03T11:42:53Z
dc.date.issued2004en_US
dc.date.modified2007-03-18T21:38:02Z
dc.identifier.issn00223751en_US
dc.identifier.doi10.1113/jphysiol.2004.069096en_AU
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.en_US
dc.description.peerreviewedYesen_US
dc.description.publicationstatusYesen_AU
dc.languageEnglishen_US
dc.language.isoen_AU
dc.publisherBlackwell Publishing Ltd.en_US
dc.publisher.placeUnited Kingdomen_US
dc.publisher.urihttp://www.blackwell-synergy.com/doi/full/10.1113/jphysiol.2004.069096en_AU
dc.relation.ispartofpagefrom519en_US
dc.relation.ispartofpageto533en_US
dc.relation.ispartofissue2en_US
dc.relation.ispartofjournalThe Journal of Physiologyen_US
dc.relation.ispartofvolume559en_US
dc.subject.fieldofresearchcode270603en_US
dc.titleSlow skeletal muscles of the mouse have greater initial efficiency than fast muscles but the same net efficiencyen_US
dc.typeJournal articleen_US
dc.type.descriptionC1 - Peer Reviewed (HERDC)en_US
dc.type.codeC - Journal Articlesen_US
gro.facultyGriffith Health, School of Rehabilitation Sciencesen_US
gro.rights.copyrightCopyright 2004 Blackwell Publishing. The definitive version is available at [www.blackwell-synergy.com.]en_AU
gro.date.issued2004
gro.hasfulltextNo Full Text


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