Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-12-29
pubmed:abstractText
Soleus muscle fibers from the rat display a reduction in peak power and Ca2+ sensitivity after hindlimb suspension. To examine human responses to non-weight bearing, we obtained soleus biopsies from eight adult men before and immediately after 17 days of bed rest (BR). Single chemically skinned fibers were mounted between a force transducer and a servo-controlled position motor and activated with maximal (isotonic properties) and/or submaximal (Ca2+ sensitivity) levels of free Ca2+. Gel electrophoresis indicated that all pre- and post-BR fibers expressed type I myosin heavy chain. Post-BR fibers obtained from one subject displayed increases in peak power and Ca2+ sensitivity. In contrast, post-BR fibers obtained from the seven remaining subjects showed an average 11% reduction in peak power (P < 0.05), with each individual displaying a 7-27% reduction in this variable. Post-BR fibers from these subjects were smaller in diameter and produced 21% less force at the shortening velocity associated with peak power. However, the shortening velocity at peak power output was elevated 13% in the post-BR fibers, which partially compensated for their lower force. Post-BR fibers from these same seven subjects also displayed a reduced sensitivity to free Ca2+ (P < 0.05). These results indicate that the reduced functional capacity of human lower limb extensor muscles after BR may be in part caused by alterations in the cross-bridge mechanisms of contraction.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1949-56
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Force-velocity-power and force-pCa relationships of human soleus fibers after 17 days of bed rest.
pubmed:affiliation
Department of Biology, Marquette University, Milwaukee, Wisconsin 53201, USA.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, Non-P.H.S.