| Myosin phosphorylation, twitch potentiation, and fatigue in human skeletal muscle. | |
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MedLine Citation:
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PMID: 2383804 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Twitch tension and phosphate incorporation into the phosphorylatable light chains (P-light chains) of myosin were studied during a 10-min recovery period following a 10- or 60-s maximal voluntary isometric contraction (MVC) in 18 subjects. Analysis of muscle biopsy samples obtained before, immediately after, 1 min, and 10 min following the 10-s MVC revealed that the 10-s MVC produced a modest but transient metabolic displacement from rest, a 35% decrease in phosphocreatine, and a threefold elevation in lactate concentration. Immediately after the 60-s MVC, ATP was decreased by 20%, phosphocreatine decreased by 84%, and lactate was elevated by 15-fold. Lactate remained elevated over the 10-min recovery period. Twitch force was maximally potentiated following the 10-s MVC and declined to rest by 10 min of recovery. Twitch force was 0.66 of rest value immediately after the 60-s MVC, then increased over the next 4 min to reach a potentiated value 21% greater than rest, before declining. Significant phosphate incorporation into P-light chains was observed immediately after both contractions, but dephosphorylation to rest values at the end of recovery was only noted for the 60-s condition. These results demonstrate an inconsistent relationship between twitch tension enhancement and P-light chain phosphorylation in the in vivo human model. |
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Authors:
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M E Houston; R W Grange |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Canadian journal of physiology and pharmacology Volume: 68 ISSN: 0008-4212 ISO Abbreviation: Can. J. Physiol. Pharmacol. Publication Date: 1990 Jul |
Date Detail:
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Created Date: 1990-09-20 Completed Date: 1990-09-20 Revised Date: 2009-11-19 |
Medline Journal Info:
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Nlm Unique ID: 0372712 Medline TA: Can J Physiol Pharmacol Country: CANADA |
Other Details:
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Languages: eng Pagination: 908-13 Citation Subset: IM |
Affiliation:
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Department of Kinesiology, University of Waterloo, Ont., Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Triphosphate
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metabolism Adult Electric Stimulation Female Glycogen / metabolism Humans Isometric Contraction Lactates / metabolism Male Muscle Contraction* Muscles / metabolism, physiology* Myosins / metabolism* Phosphates / metabolism Phosphocreatine / metabolism Phosphorylation |
| Chemical | |
Reg. No./Substance:
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0/Lactates; 0/Phosphates; 56-65-5/Adenosine Triphosphate; 67-07-2/Phosphocreatine; 9005-79-2/Glycogen; EC 3.6.4.1/Myosins |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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