Document Detail


Differential responses of glycogen synthase to ischaemia and ischaemic contraction in human skeletal muscle.
MedLine Citation:
PMID:  9023518     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The importance of metabolic changes associated with contraction in the activation of glycogen synthase (GS) during recovery from exercise in human skeletal muscle has been investigated. Subjects underwent two experimental treatments: 15 s of ischaemic isometric contraction at 66% of maximal force, and 40 min circulatory occlusion. Biopsies were taken from the quadriceps femoris muscle at rest, at the end of each treatment, and 5 min post-treatment. The decreases in phosphocreatine (approximately 50%), and increases in glucose 6-phosphate (approximately 3-fold) and lactate (approximately 8-fold) were similar during contraction and occlusion, indicating similar degrees of anaerobic ATP turnover and glycogen breakdown. Glycogen breakdown during each treatment was estimated to correspond to < 5% of the basal muscle glycogen content. GS fractional activity decreased approximately 10% after contraction and approximately 30% after occlusion (P < 0.05 vs. contraction). During recovery from contraction, GS fractional activity increased to 20% above the rest value, whereas no further change occurred during recovery from occlusion (P < 0.001 vs. recovery from contraction). These data demonstrate that the increase in GS fractional activity during recovery from isometric contraction does not require significant glycogen breakdown during the contraction, and is not a consequence of the measured metabolic changes associated with the contraction.
Authors:
A Katz
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Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Experimental physiology     Volume:  82     ISSN:  0958-0670     ISO Abbreviation:  Exp. Physiol.     Publication Date:  1997 Jan 
Date Detail:
Created Date:  1997-05-28     Completed Date:  1997-05-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9002940     Medline TA:  Exp Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  203-11     Citation Subset:  IM    
Affiliation:
Department of Surgical Sciences, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
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MeSH Terms
Descriptor/Qualifier:
Adult
Glycogen Synthase / metabolism*
Humans
Ischemia / enzymology*
Isometric Contraction / physiology
Male
Muscle, Skeletal / blood supply,  enzymology*,  physiology*
Phosphorylases / metabolism
Regional Blood Flow / physiology
Chemical
Reg. No./Substance:
EC 2.4.1.-/Phosphorylases; EC 2.4.1.11/Glycogen Synthase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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