Linked Life Data

16446038

Source:http://linkedlifedata.com/resource/pubmed/id/16446038

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-3-13
pubmed:abstractText
The monocarboxylate transporters 1 and 4 are expressed in brain as well as in skeletal muscle and play important roles in the energy metabolism of both tissues. In brain, monocarboxylate transporter 1 occurs in astrocytes, ependymocytes, and endothelial cells while monocarboxylate transporter 4 appears to be restricted to astrocytes. In muscle, monocarboxylate transporter 1 is enriched in oxidative muscle fibers whereas monocarboxylate transporter 4 is expressed in all fibers, with the lowest levels in oxidative fiber types. The mechanisms regulating monocarboxylate transporter 1 and monocarboxylate transporter 4 expression are not known. We hypothesized that the expression of these transporters would be sensitive to long term changes in metabolic activity level. This hypothesis can be tested in rat skeletal muscle, where permanent changes in activity level can be induced by cross-reinnervation. We transplanted motor axons originally innervating the fast-twitch extensor digitorum longus muscle to the slow-twitch soleus muscle and vice versa. Four months later, microscopic analysis revealed transformation of muscle fiber types in the cross-reinnervated muscles. Western blot analysis showed that monocarboxylate transporter 1 was increased by 140% in extensor digitorum longus muscle and decreased by 30% in soleus muscle after cross-reinnervation. In contrast, cross-reinnervation induced a 62% decrease of monocarboxylate transporter 4 in extensor digitorum longus muscle and a 1300% increase in soleus muscle. Our findings show that cross-reinnervation causes pronounced changes in the expression levels of monocarboxylate transporter 1 and monocarboxylate transporter 4, probably as a direct consequence of the new pattern of nerve impulses. The data indicate that the mode of innervation dictates the expression of monocarboxylate transporter proteins in the target cells and that the change in monocarboxylate transporter isoform profile is an integral part of the muscle fiber transformation that occurs after cross-reinnervation. Our findings support the hypothesis that the expression of monocarboxylate transporter 1 and monocarboxylate transporter 4 in excitable tissues is regulated by activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1105-13
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Cross-reinnervation changes the expression patterns of the monocarboxylate transporters 1 and 4: An experimental study in slow and fast rat skeletal muscle.
pubmed:affiliation
Centre for Molecular Biology and Neuroscience, and Department of Anatomy, IMB, University of Oslo, POB 1105 Blindern, N-0317 Oslo, Norway. l.h.bergersen@medisin.uio.no
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't