Linked Life Data

1295669

Source:http://linkedlifedata.com/resource/pubmed/id/1295669

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1993-4-22
pubmed:abstractText
The rapid changes in brain extracellular ion concentrations that occur with anoxia are important in understanding the pathophysiology of anoxic-ischemic brain injury. While previous studies have focused on the ionic changes that occur in gray matter areas of the brain, white matter (WM) is also damaged by anoxia. We describe the changes in extracellular K+ concentration ([K+]o) and extracellular pH (pHo) that accompany anoxia in WM, and present new results indicating that glial cells directly contribute to the observed fluctuations of these ions. Anoxia-induced changes in [K+]o and pHo were measured with ion-selective microelectrodes in the isolated rat optic nerve, a typical WM tract. To assess the contribution of glial cells, recordings were also made in optic nerves that contained only glial cells (produced by neonatal enucleation). Anoxia in WM produced less extreme changes in [K+]o and pHo than are known to occur in gray matter; in WM during anoxia, the average maximum [K+]o was 14 +/- 2.9 mM (bath [K+]o = 3 mM) and the average maximum acid shift was 0.31 +/- 0.07 pH unit. These extracellular ionic changes were accompanied by rapid shrinkage of extracellular space volume. The ability of optic nerve axons to conduct action potentials was lost in temporal association with the increase in [K+]o. Increasing bath glucose concentration from 10 to 20 mM resulted in a much larger acid shift during anoxia (0.58 +/- 0.08 pH unit) and a smaller average increase in [K+]o (9.2 +/- 2.6 mM). The increased glucose concentration presumably enhanced anaerobic metabolism, leading to extracellular lactate accumulation and a greater acid shift.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0008-4212
pubmed:author
pubmed:issnType
Print
pubmed:volume
70 Suppl
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
S181-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Anoxia-induced extracellular ionic changes in CNS white matter: the role of glial cells.
pubmed:affiliation
Department of Neurology, Yale University School of Medicine, New Haven, CT 06510.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.