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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1983-12-17
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pubmed:abstractText |
Glutamate is simultaneously taken up and released by perfused rat liver, as shown by 14CO2 production from [1-14C]glutamate in the presence of a net glutamate release by the liver, turning to a net glutamate uptake at portal glutamate concentrations above 0.3 mM. 14CO2 production from portal [1-14C]glutamate is decreased by about 60% in the presence of ammonium ions. This effect is not observed during inhibition of glutamine synthetase by methionine sulfoximine. 14CO2 production from [1-14C]glutamate is not influenced by glutamine. Also, when glutamate accumulates intracellularly during the metabolism of glutamine (added at high concentrations, 5 mM), 14CO2 production from [1-14C]glutamate is not affected. If labeled glutamate is generated intracellularly from added [U-14C]proline, stimulation of glutamine synthesis by ammonium ions did not affect 14CO2 production from [U-14C]proline. After induction of a perivenous liver cell necrosis by CCL4, i.e. conditions associated with an almost complete loss of perivenous glutamine synthesis but no effect on periportal urea synthesis, 14CO2 production from [1-14C]glutamate is decreased by about 70%. The results are explained by hepatocyte heterogeneity in glutamate metabolism and indicate a predominant uptake of glutamate (that reaches the liver by the vena portae) by the small perivenous population of glutamine-synthesizing hepatocytes, whereas glutamate production from glutamine or proline is predominantly periportal. In view of the size of the glutamine synthetase-containing hepatocyte pool [Gebhardt, R. and Mecke, D. (1983) EMBO J. 2, 567-570], glutamate transport capacity of these hepatocytes would be about 20-fold higher as compared to other hepatocytes.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
2
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pubmed:volume |
136
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
421-5
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:6414814-Animals,
pubmed-meshheading:6414814-Biological Transport,
pubmed-meshheading:6414814-Carbon Dioxide,
pubmed-meshheading:6414814-Chemical Phenomena,
pubmed-meshheading:6414814-Chemistry,
pubmed-meshheading:6414814-Glutamates,
pubmed-meshheading:6414814-Liver,
pubmed-meshheading:6414814-Male,
pubmed-meshheading:6414814-Perfusion,
pubmed-meshheading:6414814-Quaternary Ammonium Compounds,
pubmed-meshheading:6414814-Rats,
pubmed-meshheading:6414814-Rats, Inbred Strains
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pubmed:year |
1983
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pubmed:articleTitle |
Hepatocyte heterogeneity in glutamate uptake by isolated perfused rat liver.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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