Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1996-12-3
pubmed:abstractText
The question as to whether glutamine and glucose are both required for optimal growth of glioma cells is studied through the role of these substrates on the metabolism of the cells. C6 rat glioma cells grow only very slowly when glutamine is omitted from the culture medium. The rates of glucose consumption and lactate production on confluent cells in glutamine-free medium were 0.88 +/- 0.09 and 1.06 +/- 0.25 mumol/h/mg protein, respectively. In the presence of 4 mM glutamine, glucose utilization increase to 60% leading to a 45% increase of lactate production. We have studied the kinetics of enrichment of intracellular glutamate at C2, C3 and C4 positions on cells incubated with 5 mM 99% enriched [1-(13)C]glucose in the presence or the absence of glutamine in the incubation medium. The specific enrichments at metabolic steady state of all carbon positions were the same under both conditions, but we observed a significantly reduced rate of 13C incorporation in the presence of glutamine, showing an isotopic dilution of tricarboxylic acid cycle intermediates and indicating the use of this amino acid as an anaplerotic substrate. The fact that no dilution occurred at the level of pyruvate suggests strongly the lack of glutaminolysis in these cells. The main conclusion from this work is that glutamine metabolism in C6 cells appears complementary to that of glucose as far as energy production and carbon sources for the growing of the cells are concerned: glutamine is mainly utilized for anaplerosis as carbon donor to replenish the tricarboxylic acid cycle; it is not a substrate for energy metabolism. In contrast, glucose is poorly anaplerotic and is essentially used as energetic fuel by the C6 cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-9084
pubmed:author
pubmed:issnType
Print
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
155-64
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Glucose and glutamine metabolism in C6 glioma cells studied by carbon 13 NMR.
pubmed:affiliation
Unité de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS, Université de Bordeaux 2, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't