| Glyceroneogenesis and the supply of glycerol-3-phosphate for glyceride-glycerol synthesis in liver slices of fasted and diabetic rats. | |
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MedLine Citation:
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PMID: 17726141 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The pathways of glycerol-3-phosphate (G3P) generation for glyceride synthesis were examined in precision-cut liver slices of fasted and diabetic rats. The incorporation of 5 mM [U-(14)C]glucose into glyceride-glycerol, used to evaluate G3P generation via glycolysis, was reduced by approximately 26-36% in liver slices of fasted and diabetic rats. The glycolytic flux was reduced by approximately 60% in both groups. The incorporation of 1.0 mM [2-(14)C]pyruvate into glyceride-glycerol (glyceroneogenesis) increased approximately 50% and approximately 36% in slices of fasted and diabetic rats, respectively, which also showed a two-fold increase in the activity phosphoenolpyruvate carboxykinase. The increased incorporation of 1.0 mM [2-(14)C]pyruvate into glyceride-glycerol by slices of fasted rats was not affected by the addition of 5 mM glucose to the incubation medium. The activity of glycerokinase and the incorporation of 1 mM [U-(14)C]glycerol into glyceride-glycerol, evaluators of G3P formation by direct glycerol phosphorylation, did not differ significantly from controls in slices of the two experimental groups. Rates of incorporation of 1 mM [2-(14)C]pyruvate and [U-(14)C]glycerol into glucose of incubation medium (gluconeogenesis) were approximately 140 and approximately 20% higher in fasted and diabetic slices than in control slices. It could be estimated that glyceroneogenesis by liver slices of fasted rats contributed with approximately 20% of G3P generated for glyceride-glycerol synthesis, the glycolytic pathway with approximately 5%, and direct phosphorylation of glycerol by glycerokinase with approximately 75%. Pyruvate contributed with 54% and glycerol with 46% of gluconeogenesis. The present data indicate that glyceroneogenesis has a significant participation in the generation of G3P needed for the increased glyceride-glycerol synthesis in liver during fasting and diabetes. |
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Authors:
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Maria Emilia Soares Martins-Santos; Valéria Ernestânia Chaves; Danúbia Frasson; Renata Polessi Boschini; Maria Antonieta Rissato Garófalo; Isis do Carmo Kettelhut; Renato Hélios Migliorini |
Publication Detail:
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Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't Date: 2007-08-28 |
Journal Detail:
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Title: American journal of physiology. Endocrinology and metabolism Volume: 293 ISSN: 0193-1849 ISO Abbreviation: Am. J. Physiol. Endocrinol. Metab. Publication Date: 2007 Nov |
Date Detail:
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Created Date: 2007-11-08 Completed Date: 2007-12-18 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 100901226 Medline TA: Am J Physiol Endocrinol Metab Country: United States |
Other Details:
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Languages: eng Pagination: E1352-7 Citation Subset: IM |
Affiliation:
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Department of Biochemistry and Immunology, School of Medicine, USP 14049-900 Ribeirão Preto, São Paulo, Brazil. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Triphosphate
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metabolism Animals Carbon Radioisotopes / diagnostic use Diabetes Mellitus, Experimental / enzymology, metabolism* Food Deprivation / physiology Glucose / metabolism Glycerides / biosynthesis* Glycerol / metabolism Glycerol Kinase / metabolism Glycerophosphates / metabolism* Liver / enzymology, metabolism* Male Phosphoenolpyruvate Carboxykinase (ATP) / metabolism Pyruvic Acid / metabolism Rats Rats, Wistar Triglycerides / metabolism |
| Chemical | |
Reg. No./Substance:
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0/Carbon Radioisotopes; 0/Glycerides; 0/Glycerophosphates; 0/Triglycerides; 127-17-3/Pyruvic Acid; 50-99-7/Glucose; 56-65-5/Adenosine Triphosphate; 56-81-5/Glycerol; 57-03-4/alpha-glycerophosphoric acid; EC 2.7.1.30/Glycerol Kinase; EC 4.1.1.49/Phosphoenolpyruvate Carboxykinase (ATP) |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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