Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-2-19
pubmed:abstractText
The rate of glutaminase-dependent metabolism of glutamine in intact astrocytes was determined under conditions in which the extracellular concentration of glutamine was varied between 0.2 and 3.2 mM glutamine for control and dibutyryl cyclic AMP (dBcAMP)-treated cells. Glutamine metabolism by intact cells increased with increasing extracellular glutamine when calculations were based on the extracellular specific activity of glutamine. However, when the rate was based on the intracellular specific activity of glutamine, the rate of glutamine metabolism was independent of the media glutamine concentration. Similar results were obtained when cells were treated with dBcAMP, although the rates were approximately twice as high compared to untreated cells. The rate of formation of 14CO2 from [1-14C]glutamine and [1-14C]glutamate, based on the extracellular specific activities, were 93 +/- 5 and 40 +/- 4 nmol/mg protein/h, respectively. Oxidation rates based on the experimentally determined intracellular specific activity of glutamine and glutamate were 144 +/- 8 and 209 +/- 18 nmol/mg protein/h, respectively. In dBcAMP-treated astrocytes, the oxidation rates were higher than in untreated cells. These studies demonstrate that determination of the specific activity of compounds inside the cell aids in the interpretation of metabolic studies with intact cells and that both the initial steps of glutamine metabolism and the rate of 14CO2 formation from 14C-glutamine via the TCA cycle were increased in dBcAMP-treated astrocytes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0378-5866
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
224-30
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Use of intracellular versus extracellular specific activities in calculation of glutamine metabolism in astrocytes: effect of dibutyryl cyclic AMP.
pubmed:affiliation
Department of Pediatrics, University of Maryland School of Medicine, Baltimore, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.