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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1990-11-1
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pubmed:abstractText |
In rat liver microsomes, 2-methyl-1,4-naphthoquinone (menadione) inhibits cytochrome P450 (cyt P450)-mediated aniline-p-hydroxylation and aminopyrine-N-demethylation with Ki values of 12 and 14.5 microM, respectively. The inhibitions of aniline-p-hydroxylation and aminopyrine-N-demethylation are mixed uncompetitive-noncompetitive and mixed competitive-noncompetitive, respectively. NADP antagonizes the inhibitory effect of menadione on aniline-p-hydroxylase activity but not that on aminopyrine-N-demethylase activity. Menadione does not give rise to any spectral change of cyt P450, but modifies the type I binding spectrum induced by aminopyrine. In contrast, menadione does not change the type II binding spectrum induced by aniline. These results indicate that menadione may inhibit aniline-p-hydroxylase activity by acting as a substrate for NADPH-cyt P450 reductase in the place of cyt P450 and inhibit aminopyrine-N-demethylase activity by impairing the binding of aminopyrine to cyt P450.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Aminopyrine N-Demethylase,
http://linkedlifedata.com/resource/pubmed/chemical/Aniline Hydroxylase,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System,
http://linkedlifedata.com/resource/pubmed/chemical/NADP,
http://linkedlifedata.com/resource/pubmed/chemical/Vitamin K
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0041-008X
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
105
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
333-9
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2219123-Aminopyrine N-Demethylase,
pubmed-meshheading:2219123-Aniline Hydroxylase,
pubmed-meshheading:2219123-Animals,
pubmed-meshheading:2219123-Cytochrome P-450 Enzyme System,
pubmed-meshheading:2219123-Kinetics,
pubmed-meshheading:2219123-Male,
pubmed-meshheading:2219123-Microsomes, Liver,
pubmed-meshheading:2219123-NADP,
pubmed-meshheading:2219123-Oxidation-Reduction,
pubmed-meshheading:2219123-Rats,
pubmed-meshheading:2219123-Rats, Inbred Strains,
pubmed-meshheading:2219123-Spectrophotometry,
pubmed-meshheading:2219123-Vitamin K
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pubmed:year |
1990
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pubmed:articleTitle |
Inhibition of rat liver monooxygenase activities by 2-methyl-1,4-naphthoquinone (menadione).
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pubmed:affiliation |
Department of Pharmacology, University of Padova, Italy.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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