| Glucocorticoid stimulation of tetrahydrobiopterin levels and phenylalanine hydroxylase activity in rat hepatoma cells. | |
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MedLine Citation:
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PMID: 2775531 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Incubation of H4-II-E-C3 rat hepatoma cells with either hydrocortisone or dexamethasone resulted in 3- to 5-fold increases in the levels of both phenylalanine hydroxylase and its essential cofactor, tetrahydrobiopterin. Maximum elevation of phenylalanine hydroxylase was noted after 24 h of incubation, whereas significant increases in tetrahydrobiopterin were found only after 48 h exposure of the cells to glucocorticoids. Removal of hormone from the culture medium resulted in rapid loss of cell tetrahydrobiopterin, but a much slower decline in the level of phenylalanine hydroxylase. Thus, although the levels of both phenylalanine hydroxylase and tetrahydrobiopterin in rat hepatoma cells are regulated by glucocorticoids, this regulation is apparently not strictly coordinated. Nevertheless, control of cellular tetrahydrobiopterin levels may be an important regulator of hepatic phenylalanine catabolism since significant increases in the ability of intact rat liver cells to hydroxylate phenylalanine were observed only after 48 h exposure to glucocorticoids, in correlation with increases in cell tetrahydrobiopterin content. |
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Authors:
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M A Parniak; J Pilkington |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Biochemistry and cell biology = Biochimie et biologie cellulaire Volume: 67 ISSN: 0829-8211 ISO Abbreviation: Biochem. Cell Biol. Publication Date: 1989 Jun |
Date Detail:
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Created Date: 1989-10-20 Completed Date: 1989-10-20 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8606068 Medline TA: Biochem Cell Biol Country: CANADA |
Other Details:
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Languages: eng Pagination: 293-6 Citation Subset: IM |
Affiliation:
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Lady Davis Institute for Medical Research, Sir Mortimer B. Davis, Jewish General Hospital, Montreal, Que., Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Biopterin / analogs & derivatives*, metabolism Dexamethasone / pharmacology* Hydrocortisone / pharmacology* Liver Neoplasms, Experimental / metabolism* Phenylalanine Hydroxylase / metabolism* Rats Tumor Cells, Cultured / drug effects, metabolism |
| Chemical | |
Reg. No./Substance:
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17528-72-2/5,6,7,8-tetrahydrobiopterin; 22150-76-1/Biopterin; 50-02-2/Dexamethasone; 50-23-7/Hydrocortisone; EC 1.14.16.1/Phenylalanine Hydroxylase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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