| Dietary modulation of phase 1 and phase 2 activities with benzo(a)pyrene and related compounds in the intestine but not the liver of the channel catfish, Ictalurus punctatus. | |
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MedLine Citation:
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PMID: 9172953 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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These studies demonstrated that intestinal mucosa of the channel catfish contained activities comparable with liver for several phase 2 xenobiotic-metabolizing enzymes, and showed that CYP1A-dependent monooxygenase activities were inducible in intestine but not liver by dietary exposure to low concentrations of the Ah agonist, beta-naphthoflavone (BNF). The diets administered were laboratory-prepared, semisynthetic pellets of known composition, commercial chow, or chow supplemented with BNF at 10 or 100 mg BNF/kg chow. Very low intestinal benzo(a)pyrene hydroxylase [aryl hydrocarbon hydroxylase (AHH)] and ethoxyresorufin O-deethylase (EROD) activities were found in catfish fed the semisynthetic diet. Intestinal EROD and AHH activities were elevated by the commercial chow diet and further induced by supplementation with 10, but not 100, mg BNF/kg diet. In vitro studies showed that catfish EROD and AHH activities were sensitive to inhibition by BNF, with mean IC50 values of 0.078 and 2.2 microM, respectively. Thus, residues of BNF retained in intestinal mucosa may have masked monooxygenase induction in catfish fed the 100 mg BNF/kg diet. Microsomal UDP-glucuronosyltransferase and cytosolic PAPS-sulfotransferase activities with 3-hydroxybenzo(a)pyrene as substrate were largely unaffected by the diets studied, and intestinal activities were similar to hepatic activities. Glutathione S-transferase activity was slightly induced in intestinal, but not hepatic cytosol of catfish treated with BNF at the 10 mg/kg diet level relative to chow controls. Epoxide hydrolase activity with styrene oxide as substrate was not affected by diet in intestinal microsomes. |
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Authors:
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M O James; A H Altman; K Morris; K M Kleinow; Z Tong |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Drug metabolism and disposition: the biological fate of chemicals Volume: 25 ISSN: 0090-9556 ISO Abbreviation: Drug Metab. Dispos. Publication Date: 1997 Mar |
Date Detail:
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Created Date: 1997-06-05 Completed Date: 1997-06-05 Revised Date: 2009-11-19 |
Medline Journal Info:
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Nlm Unique ID: 9421550 Medline TA: Drug Metab Dispos Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 346-54 Citation Subset: IM |
Affiliation:
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Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville 32610-0485, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Benzo(a)pyrene / metabolism* Benzopyrene Hydroxylase / metabolism Cytochrome P-450 CYP1A1 / metabolism Cytochrome P-450 Enzyme System / metabolism Diet* Enzyme Induction Epoxide Hydrolases / metabolism Female Ictaluridae Intestinal Mucosa / drug effects*, enzymology* Liver / drug effects*, enzymology* Male beta-Naphthoflavone / pharmacology |
| Grant Support | |
ID/Acronym/Agency:
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ES05781/ES/NIEHS NIH HHS |
| Chemical | |
Reg. No./Substance:
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50-32-8/Benzo(a)pyrene; 6051-87-2/beta-Naphthoflavone; 9035-51-2/Cytochrome P-450 Enzyme System; EC 1.14.14.-/Benzopyrene Hydroxylase; EC 1.14.14.1/Cytochrome P-450 CYP1A1; EC 3.3.2.-/Epoxide Hydrolases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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