Linked Life Data

17234955

Source:http://linkedlifedata.com/resource/pubmed/id/17234955

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-5-3
pubmed:abstractText
We investigated the role of limitations in aerobic metabolism, glycolysis, and membrane excitability for development of high-frequency fatigue in isolated rat soleus muscle. Muscles mounted on force transducers were incubated in buffer bubbled with 5% CO(2) and either 95% O(2) (oxygenated) or 95% N(2) (anoxic) and stimulated at 60 Hz continuously for 30-120 s or intermittently for 120 s. Cyanide (2 mM) and 2-deoxyglucose (10 mM) were used to inhibit aerobic metabolism and both glycolysis and aerobic metabolism, respectively. Excitability was reduced by carbacholine (10 microM), a nicotinic ACh receptor agonist, or ouabain (10 microM), an Na(+)-K(+) pump inhibitor. Membrane excitability was measured by recording M waves. Intracellular Na(+) and K(+) contents and membrane potentials were measured by flame photometry and microelectrodes, respectively. During 120 s of continuous stimulation, oxygenated and anoxic muscles showed the same force loss. In oxygenated muscles, cyanide did not alter force loss for up to 90 s, whereas 2-deoxyglucose increased force loss (by 19-69%; P < 0.01) from 14 s of stimulation. In oxygenated muscles, 60 s of stimulation reduced force, M wave area, and amplitude by 70-90% (P < 0.001). Carbacholine or ouabain increased intracellular Na(+) content (P < 0.001), induced a 7- to 8-mV membrane depolarization (P < 0.001), and accelerated the rate of force loss (by 250-414%) during 30 s of stimulation (P < 0.001). Similar effects were seen with intermittent stimulation. In conclusion, limitations in glycolysis and subsequently also in aerobic metabolism, as well as membrane excitability but not aerobic metabolism alone, appear to play an important role in the development of high-frequency fatigue in isolated rat soleus muscle.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0363-6119
pubmed:author
pubmed:issnType
Print
pubmed:volume
292
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
R2001-11
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
The importance of limitations in aerobic metabolism, glycolysis, and membrane excitability for the development of high-frequency fatigue in isolated rat soleus muscle.
pubmed:affiliation
Institute of Physiology and Biophysics, Univ of Aarhus, Ole Worms Allé 160, Arhus C, Denmark. km@fi.au.dk
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't