Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-8-8
pubmed:abstractText
Traumatic brain injury is followed by increased extracellular glutamate concentration. Uptake of glutamate is mainly mediated by the glial glutamate transporters GLAST and GLT-1. Extent and distribution of GLAST and GLT-1 were studied in a rat model of controlled cortical impact injury (CCII). Western Blot analysis revealed lowest levels of GLAST and GLT-1 with a decrease by 40%-54% and 42%-49% between 24 and 72 h posttrauma. By 8 h after CCII, CSF glutamate levels were increased (10.5 microM vs. 2.56 microM in controls; P < 0.001), reaching maximum values by 48 h. A significant increase in de novo GLAST and GLT-1 expressing ramified microglia was observed within 4 h, reached a stable level by 48 h, and remained high up to 72 h after CCII. Furthermore, ramified microglia de novo expressed the neuronal glutamate transporter EAAC1 after CCII. Following CCII, GLAST/GLT-1 and GFAP coexpressing astrocytes were immediately reduced, reaching minimum levels within 8 h. This reduction of expression could be either due to protein downregulation or loss of astrocytes. At 72 h, a marked population of GLAST- and GLT-1-positive reactive astrocytes appeared. These results support the hypothesis that reduced astrocytic GLAST and GLT-1 protein levels following CCII contribute to evolving secondary injury. Microglia are capable of de novo expressing glutamate transporter proteins, indicating that the expression of glial and neuronal glutamate transporters is not restricted to a specific glial or neuronal lineage. Ramified microglia may play an important compensatory role in the early regulation of extracellular glutamate after CCII.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0894-1491
pubmed:author
pubmed:copyrightInfo
Copyright 2001 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-79
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11494408-ATP-Binding Cassette Transporters, pubmed-meshheading:11494408-Amino Acid Transport System X-AG, pubmed-meshheading:11494408-Animals, pubmed-meshheading:11494408-Astrocytes, pubmed-meshheading:11494408-Brain Injuries, pubmed-meshheading:11494408-Cerebral Cortex, pubmed-meshheading:11494408-Excitatory Amino Acid Transporter 2, pubmed-meshheading:11494408-Extracellular Space, pubmed-meshheading:11494408-Glial Fibrillary Acidic Protein, pubmed-meshheading:11494408-Glutamic Acid, pubmed-meshheading:11494408-Hippocampus, pubmed-meshheading:11494408-Immunohistochemistry, pubmed-meshheading:11494408-Lectins, pubmed-meshheading:11494408-Macrophages, pubmed-meshheading:11494408-Male, pubmed-meshheading:11494408-Microglia, pubmed-meshheading:11494408-Rats, pubmed-meshheading:11494408-Rats, Sprague-Dawley, pubmed-meshheading:11494408-Receptors, Neurotransmitter, pubmed-meshheading:11494408-Thalamus, pubmed-meshheading:11494408-Time Factors
pubmed:year
2001
pubmed:articleTitle
Early expression of glutamate transporter proteins in ramified microglia after controlled cortical impact injury in the rat.
pubmed:affiliation
Institute of Neuropathology, Charité, Humboldt University, Berlin, Germany. frank.van_landeghem@charite.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't