Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1972-6-13
pubmed:abstractText
Initial energy utilization in the twitch is visualized as the result of the activity of two distinct processes. The first is the calcium-pumping activity of the sarcoplasmic reticulum, which has a constant energy requirement under normal conditions. The second is the chemomechanical transduction process consisting of a variable number of quantal contractile events, each with a fixed enthalpy equal to the molecular enthalpy of adenosine triphosphate (ATP) hydrolysis in vivo. This enthalpy appears either as heat or as contractile element work. Total enthalpy varies according to the number of quantal contractile events that occur in the twitch cycle. The basis of the variation is suggested to be velocity-dependent activity of the actomyosin ATPase, allowing more quantal events to occur in a contraction cycle when shortening occurs. The classical designation "activation heat" is held to be appropriate for the first process. The partition of the enthalpy of the second process that is currently in vogue is held to be misleading and a new formulation is suggested in which the properties of the quantal contractile event are reflected in general terms. The formulation of the proposed transduction model represents a conceptual return to the viscoelastic theory, but at a quantal level. The model can explain the results of the preceding paper and is adaptable to different muscles without having to postulate fundamental differences in energy utilization.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-13840533, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-13999359, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-14132965, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-14169343, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-14179458, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-14911816, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-4181952, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-4222046, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-4227924, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-4622691, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-4894870, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-5318082, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-5770880, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-5797329, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-5815819, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-5938825, http://linkedlifedata.com/resource/pubmed/commentcorrection/4259475-5971769
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
227-36
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1972
pubmed:articleTitle
An energetic model of muscle contraction.
pubmed:publicationType
Journal Article