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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3
|
| pubmed:dateCreated |
1990-2-21
|
| pubmed:abstractText |
Glucagon stimulates flux through the glycine cleavage system (GCS) in isolated rat hepatocytes (Jois, M., Hall, B., Fewer, K., and Brosnan, J. T. (1989) J. Biol. Chem. 264, 3347-3351. In the present study, flux through GCS was measured in isolated rat liver perfused with 100 nM glucagon, 1 microM epinephrine, 1 microM norepinephrine, 10 microM phenylephrine, or 100 nM vasopressin. These hormones increased flux through GCS in perfused rat liver by 100-200% above the basal rate. The possibility that the stimulation of flux by adrenergic agonists and vasopressin is mediated by increases in cytoplasmic Ca2+ which in turn could regulate mitochondrial glycine catabolism was examined by measuring flux through GCS in isolated mitochondria in the presence of 0.04-2.88 microM free Ca2+. Flux through GCS in isolated mitochondria was exquisitely sensitive to free Ca2+ in the medium; half-maximal stimulation occurred at about 0.4 microM free Ca2+ and maximal stimulation (7-fold) was reached when the free Ca2+ in the medium was 1 microM. The Vmax (nanomoles/mg protein/min) and Km (millimolar) values for the flux through GCS in intact mitochondria were 0.67 +/- 0.16 and 20.66 +/- 4.82 in the presence of 1 mM [ethylenebis(oxyethylenenitrilo)]tetraacetic acid and 3.28 +/- 0.76 and 10.98 +/- 1.91 in presence of 0.5 microM free Ca2+, respectively. The results show that the flux through GCS is sensitive to concentrations of calcium which would be achieved in the cytoplasm of hepatocytes stimulated by calcium-mobilizing hormones.
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| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Amino Acid Oxidoreductases,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Epinephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Glucagon,
http://linkedlifedata.com/resource/pubmed/chemical/Glycine,
http://linkedlifedata.com/resource/pubmed/chemical/Multienzyme Complexes,
http://linkedlifedata.com/resource/pubmed/chemical/Norepinephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Phenylephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Ruthenium Red,
http://linkedlifedata.com/resource/pubmed/chemical/Transferases,
http://linkedlifedata.com/resource/pubmed/chemical/Vasopressins,
http://linkedlifedata.com/resource/pubmed/chemical/glycine cleavage system
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jan
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
25
|
| pubmed:volume |
265
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1246-8
|
| pubmed:dateRevised |
2006-11-15
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| pubmed:meshHeading |
pubmed-meshheading:1688557-Amino Acid Oxidoreductases,
pubmed-meshheading:1688557-Animals,
pubmed-meshheading:1688557-Calcium,
pubmed-meshheading:1688557-Carrier Proteins,
pubmed-meshheading:1688557-Epinephrine,
pubmed-meshheading:1688557-Glucagon,
pubmed-meshheading:1688557-Glycine,
pubmed-meshheading:1688557-Liver,
pubmed-meshheading:1688557-Male,
pubmed-meshheading:1688557-Mitochondria, Liver,
pubmed-meshheading:1688557-Multienzyme Complexes,
pubmed-meshheading:1688557-Norepinephrine,
pubmed-meshheading:1688557-Phenylephrine,
pubmed-meshheading:1688557-Rats,
pubmed-meshheading:1688557-Rats, Inbred Strains,
pubmed-meshheading:1688557-Ruthenium Red,
pubmed-meshheading:1688557-Transferases,
pubmed-meshheading:1688557-Vasopressins
|
| pubmed:year |
1990
|
| pubmed:articleTitle |
Stimulation of glycine catabolism in isolated perfused rat liver by calcium mobilizing hormones and in isolated rat liver mitochondria by submicromolar concentrations of calcium.
|
| pubmed:affiliation |
Department of Biochemistry, Memorial University of Newfoundland, St. Johns, Canada.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|