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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1 Pt 1
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pubmed:dateCreated |
1994-8-30
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pubmed:abstractText |
Selected enzymes were measured in mixed-fiber bundles and individual fibers from rat plantaris (PL) and soleus (Sol) muscles that had undergone either 2 wk of tetrodotoxin (TTX) inactivation of the sciatic nerve, a sham operation, or were contralateral to the TTX limb. TTX disuse caused severe wasting of PL (46%) and Sol (26%) muscles and of single fibers (50% and 40%, respectively). TTX PL and Sol also had reduced (50%) glycogen content. In TTX, PL, and Sol macro samples and single fibers, the activities (mol.h-1.kg dry wt-1) of hexokinase, glycogen phosphorylase, and lactate dehydrogenase were higher, lower, and unchanged, respectively, compared with controls. Single-fiber data showed that these changes occurred in all fibers. In TTX PL macro samples, activities of glycerol-3-phosphate dehydrogenase (GPDH), pyruvate kinase (PK), malate dehydrogenase (MDH), citrate synthase (CS), beta-hydroxyacyl-CoA dehydrogenase (BOAC), and thiolase were, or tended to be, lower. Single-fiber data showed a disappearance of high-oxidative moderate glycolytic fibers (i.e., usually fast-twitch oxidative in control) and the appearance of more fibers with a metabolic enzyme profile approaching that of control slow-oxidative fibers. In TTX Sol macro samples, GPDH and PK tended to be higher, and thiolase, BOAC, CS, and MDH lower. Single-fiber data corroborated these findings and suggested the appearance of fast fibers with downregulated oxidative enzyme profiles. Our results suggest that neuromuscular activity is a major, but not the sole, determinant of the size and metabolic heterogeneity that exists in muscle cells.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
267
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
C55-66
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8048492-Animals,
pubmed-meshheading:8048492-Female,
pubmed-meshheading:8048492-Hindlimb,
pubmed-meshheading:8048492-Muscles,
pubmed-meshheading:8048492-Paralysis,
pubmed-meshheading:8048492-Rats,
pubmed-meshheading:8048492-Rats, Sprague-Dawley,
pubmed-meshheading:8048492-Sciatic Nerve,
pubmed-meshheading:8048492-Tetrodotoxin
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pubmed:year |
1994
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pubmed:articleTitle |
Effects of tetrodotoxin-induced neural inactivation on single muscle fiber metabolic enzymes.
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pubmed:affiliation |
School of Human Movement, Laurentian University, Sudbury, Ontario, Canada.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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