Linked Life Data

10956331

Source:http://linkedlifedata.com/resource/pubmed/id/10956331

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-10-19
pubmed:abstractText
Force decline during fatigue in skeletal muscle is attributed mainly to progressive alterations of the intracellular milieu. Metabolite changes and the decline in free myoplasmic calcium influence the activation and contractile processes. This study was aimed at evaluating whether fatigue also causes persistent modifications of key myofibrillar and sarcoplasmic reticulum (SR) proteins that contribute to tension reduction. The presence of such modifications was investigated in chemically skinned fibers, a procedure that replaces the fatigued cytoplasm from the muscle fiber with a normal medium. Myofibrillar Ca(2+) sensitivity was reduced in slow-twitch muscle (for example, the pCa value corresponding to 50% of maximum tension was 6.23 +/- 0.03 vs. 5.99 + 0.05, P < 0.01, in rested and fatigued fibers) and not modified in fast-twitch muscle. Phosphorylation of the regulatory myosin light chain isoform increased in fast-twitch muscle. The rate of SR Ca(2+) uptake was increased in slow-twitch muscle fibers (14.2 +/- 1.0 vs. 19.6 +/- 2. 5 nmol. min(-1). mg fiber protein(-1), P < 0.05) and not altered in fast-twitch fibers. No persistent modifications of SR Ca(2+) release properties were found. These results indicate that persistent modifications of myofibrillar and SR properties contribute to fatigue-induced muscle force decline only in slow fibers. These alterations may be either enhanced or counteracted, in vivo, by the metabolic changes that normally occur during fatigue development.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
89
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
891-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Effects of fatigue on sarcoplasmic reticulum and myofibrillar properties of rat single muscle fibers.
pubmed:affiliation
Dipartimento di Anatomia e Fisiologia Umana, Centro di Studio per la Biologia e la Fisiopatologia Muscolare, I-35131 Padova, Italy. danielid@ux1.unipd.it
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't