| Increased glucagon action on lactate gluconeogenesis in perfused liver of dexamethasone-treated rats. | |
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MedLine Citation:
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PMID: 9367800 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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To clearly understand the hyperglycemic action of glucocorticoids, we studied the action of glucagon on lactate gluconeogenesis in the liver of rats 7 days after adrenalectomy and after treatment with 1 mg/kg dexamethasone for 7 days. The liver was isolated and cyclically perfused at 20 ml/min with 25 ml of perfusion medium containing 5 mM lactate, [U-14C]lactate, and 0-100 ng/ml glucagon. In the absence of glucagon, incorporation of [14C]lactate into glucose carbon 1 did not change significantly in the adrenalectomized rat liver (1.66 +/- 0.12% of total radioactivity for 5 min) and increased in the dexamethasone-treated rat liver (3. 61 +/- 0.54%, P < 0.01) compared to the normal rat liver (1.99 +/- 0. 28%). The response of lactate gluconeogenesis to glucagon was extremely blunted in the adrenalectomized rat liver and was much larger in the dexamethasone-treated rat than in the normal rat liver (at a glucagon concentration of 100 ng/ml, 2.13 +/- 0.33, 8.55 +/- 1. 06, and 4.61 +/- 0.53% for 5 min, respectively). Glucagon binding to liver plasma membrane was not changed by adrenalectomy and was decreased by dexamethasone treatment. These results suggest that glucocorticoids induce hyperglycemia by increasing the response to glucagon, together with the high basal activity of hepatic gluconeogenesis. In addition, these effects do not occur through changes in glucagon binding to receptors. |
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Authors:
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O Mokuda; Y Sakamoto |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Biochemical and molecular medicine Volume: 62 ISSN: 1077-3150 ISO Abbreviation: Biochem. Mol. Med. Publication Date: 1997 Oct |
Date Detail:
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Created Date: 1998-01-09 Completed Date: 1998-01-09 Revised Date: 2003-11-14 |
Medline Journal Info:
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Nlm Unique ID: 9508702 Medline TA: Biochem Mol Med Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 65-9 Citation Subset: IM |
Copyright Information:
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Copyright 1997 Academic Press. |
Affiliation:
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Third Department of Internal Medicine, Teikyo University School of Medicine, Ichihara, Chiba, 29901, Japan. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Dexamethasone / pharmacology* Glucagon / metabolism, pharmacology* Gluconeogenesis / drug effects* Lactic Acid / metabolism* Liver / metabolism* Male Perfusion Rats Rats, Wistar |
| Chemical | |
Reg. No./Substance:
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50-02-2/Dexamethasone; 50-21-5/Lactic Acid; 9007-92-5/Glucagon |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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