Linked Life Data

9178612

Source:http://linkedlifedata.com/resource/pubmed/id/9178612

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-7-8
pubmed:abstractText
The mechanisms underlying skeletal muscle functional impairment and structural changes with advanced age are only partially understood. In the present study, we support and expand our theory about alterations in sarcolemmal excitation-sarcoplasmic reticulum Ca2+ release-contraction uncoupling as a primary skeletal muscle alteration and major determinant of weakness and fatigue in mammalian species including humans. To test the hypothesis that the number of RYR1 (ryanodine receptor) uncoupled to DHPR (dihydropyridine receptor) increases with age, we performed high-affinity ligand binding studies in soleus, extensor digitorum longus (EDL) and in a pool of several skeletal muscles consisting of a mixture of fast- and slow-twitch muscle fibers in middle-aged (14-month) and old (28-months) Fisher 344 Brown Norway F1 hybrids rats. The number of DHPR, RYR1, the coupling between both receptors expressed as the DHPR/RYR1 maximum binding capacity, and their dissociation constant for high-affinity ligands were measured. The DHPR/RYR1 ratio was significantly reduced in the three groups of muscles (pool: 1.03 +/- 0.15 and 0.80 +/- 0.11, soleus: 0.44 +/- 0. 12 and 0.26 +/- 0.10, and EDL: 0.95 +/- 0.14 and 0.68 +/- 0.10, for middle-aged and old muscles, respectively). These data support the concept that DHPR-RYR1 uncoupling results in alterations in the voltage-gated sarcoplasmic reticulum Ca2+ release mechanism, decreases in myoplasmic Ca2+ elevation in response to sarcolemmal depolarization, reduced Ca2+ supply to contractile proteins and reduced contraction force with aging.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
157
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
247-53
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Dihydropyridine receptor-ryanodine receptor uncoupling in aged skeletal muscle.
pubmed:affiliation
Department of Physiology, The Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't