Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-2-6
pubmed:abstractText
We investigated the effects of 4 wk of hypodynamia on the rate of lactate transport in skeletal muscle sarcolemmal vesicles from control and hindlimb-suspended rats. Characterization of the sarcolemmal preparations was achieved with a marker enzyme (K+-p-nitrophenylphosphatase) and measurement of 1 mM [U-14C]lactate transport activity under zero-trans conditions with or without a pH gradient or the transport inhibitor alpha-hydroxycinnamate. Preparations from the two groups were not significantly different concerning yield and purification. Based on these results, we used this model to analyze the lactate transport activity after hypodynamia by tail suspension. Hindlimb suspension caused a shift from slow to fast myosin heavy chain isoforms in soleus muscles with a 40% decrease in the citrate synthase activity (from 35.3 +/- 3.7 to 21.4 +/- 2.1 mu mol x g-1 x min-1; P < 0.05). Lactate (1 mM) uptake in vesicles from the two groups was a function of time, and the rate after hindlimb suspension was significantly decreased in the suspended compared with the control group (2.25 +/- 0.44 and 3.50 +/- 0.26 nmol x min-1 x mg protein-1, respectively; P < 0.05). These differences were not observed for a higher lactate concentration (50 mM). These results suggest that the level of physical activity plays a role in the regulation of sarcolemmal lactate transport activity implicated in the exchanges of lactate between producing and utilizing cells, organs, and tissues, which are major ways of carbohydrate energy distribution in humans and others species.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
80
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
416-21
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8929578-4-Nitrophenylphosphatase, pubmed-meshheading:8929578-Animals, pubmed-meshheading:8929578-Body Weight, pubmed-meshheading:8929578-Citrate (si)-Synthase, pubmed-meshheading:8929578-Hindlimb, pubmed-meshheading:8929578-Hydrogen-Ion Concentration, pubmed-meshheading:8929578-Kinetics, pubmed-meshheading:8929578-Lactic Acid, pubmed-meshheading:8929578-Male, pubmed-meshheading:8929578-Muscle, Skeletal, pubmed-meshheading:8929578-Myofibrils, pubmed-meshheading:8929578-Myosin Heavy Chains, pubmed-meshheading:8929578-Organ Size, pubmed-meshheading:8929578-Physical Exertion, pubmed-meshheading:8929578-Rats, pubmed-meshheading:8929578-Rats, Wistar, pubmed-meshheading:8929578-Sarcolemma, pubmed-meshheading:8929578-Weightlessness, pubmed-meshheading:8929578-Weightlessness Simulation
pubmed:year
1996
pubmed:articleTitle
Lactate uptake by skeletal muscle sarcolemmal vesicles decreases after 4 wk of hindlimb unweighting in rats.
pubmed:affiliation
Laboratoire de Physiologie des Interactions, Service d'Exploration de la Fonction Respiratoire, Hopital Arnaud de Villeneuve, Montpellier, France.
pubmed:publicationType
Journal Article