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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1993-5-18
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pubmed:abstractText |
The in vitro metabolic activation of flutamide, a nitroaromatic antiandrogen which produces hepatitis in a few recipients, was first studied with male rat liver microsomes. There was no electron spin resonance evidence for the reduction of flutamide by reduced nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P-450 reductase into a nitro anion free radical. In contrast, flutamide was oxidatively transformed by cytochrome P-450 into reactive metabolite(s) that covalently bound to microsomal proteins. Covalent binding required oxygen and NADPH, and was decreased by the nucleophile glutathione and by the cytochrome P-450 inhibitors SKF 525-A, piperonyl butoxide and troleandomycin (an inhibitor of the cytochrome P-450 3A subfamily). Covalent binding was increased markedly by pretreatment with dexamethasone (an inducer of the cytochrome P-450 3A subfamily) and moderately by pretreatment with beta-naphthoflavone (an inducer of the 1A family). Covalent binding was immunoinhibited markedly by anticytochrome P-450 3A immunoglobulin G and moderately by anticytochrome P-450 1A immunoglobulin G. Covalent binding was much lower with liver microsomes from female rats (not expressing P-450 3A2). Covalent binding of flutamide also occurred with human liver microsomes (where it was inhibited by troleandomycin), and with yeast microsomes expressing human liver cytochromes P-450 1A1, 1A2 or 3A4. We concluded that flutamide was oxidatively transformed into chemically reactive metabolite(s) by rat and human cytochromes P-450, including forms belonging to the 3A and 1A subfamilies.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0022-3565
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
265
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pubmed:owner |
NLM
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pubmed:authorsComplete |
N
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pubmed:pagination |
366-72
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8386241-Animals,
pubmed-meshheading:8386241-Biotransformation,
pubmed-meshheading:8386241-Cytochrome P-450 Enzyme System,
pubmed-meshheading:8386241-Electron Spin Resonance Spectroscopy,
pubmed-meshheading:8386241-Female,
pubmed-meshheading:8386241-Flutamide,
pubmed-meshheading:8386241-Humans,
pubmed-meshheading:8386241-Isoenzymes,
pubmed-meshheading:8386241-Male,
pubmed-meshheading:8386241-Microsomes, Liver,
pubmed-meshheading:8386241-Oxidation-Reduction,
pubmed-meshheading:8386241-Rats,
pubmed-meshheading:8386241-Rats, Sprague-Dawley,
pubmed-meshheading:8386241-Reactive Oxygen Species,
pubmed-meshheading:8386241-Saccharomyces cerevisiae
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pubmed:year |
1993
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pubmed:articleTitle |
Metabolic activation of the nitroaromatic antiandrogen flutamide by rat and human cytochromes P-450, including forms belonging to the 3A and 1A subfamilies.
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pubmed:affiliation |
Institut National de la Santé et de la Recherche Medicale (INSERM) U-24, Hôpital Beaujon, Clichy, France.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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