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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
17
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pubmed:dateCreated |
1978-10-27
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pubmed:abstractText |
Hepatic microsomal heme oxygenase, the rate-limiting enzyme in heme degradation, is rapidly and markedly stimulated in selenium-deficient rats but not in controls, after a single injection of phenobarbital sodium. This stimulation occurred as early as 2 h and reached an 8- to 10-fold maximum 6 h following the drug. These observations suggest that phenobarbital rapidly and markedly enhances the degradation of hepatic heme in selenium deficiency. The cause for this rapid phenobarbital-mediated stimulation of heme degradation was investigated. It could not be ascribed to either accelerated turnover of cytochrome P-450, or enhanced lipid peroxidation possibly resulting from the concomitant lack of glutathione peroxidase in selenium deficiency. For these reasons, the metabolism of hepatic heme in the selenium-deficient rat liver was further examined during the 6-h period following phenobarbital. These studies indicated that whereas heme was synthesized much faster and to a greater extent in the selenium-deficient rat liver than in the control, its utilization in the formation of hemoproteins such as cytochrome P-450 and tryptophan pyrrolase was apparently impaired in selenium deficiency. Such defective utilization of heme in the 6-h period following phenobarbital could effectively result in a relative excess of unutilized "free" heme; hence the consequent stimulation of microsomal heme oxygenase for its disposal.
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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/5-Aminolevulinate Synthetase,
http://linkedlifedata.com/resource/pubmed/chemical/Heme,
http://linkedlifedata.com/resource/pubmed/chemical/Methylcholanthrene,
http://linkedlifedata.com/resource/pubmed/chemical/Mixed Function Oxygenases,
http://linkedlifedata.com/resource/pubmed/chemical/Phenobarbital,
http://linkedlifedata.com/resource/pubmed/chemical/Selenium
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
10
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pubmed:volume |
253
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
6203-10
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:681348-5-Aminolevulinate Synthetase,
pubmed-meshheading:681348-Animals,
pubmed-meshheading:681348-Enzyme Induction,
pubmed-meshheading:681348-Heme,
pubmed-meshheading:681348-Kinetics,
pubmed-meshheading:681348-Male,
pubmed-meshheading:681348-Methylcholanthrene,
pubmed-meshheading:681348-Microsomes, Liver,
pubmed-meshheading:681348-Mixed Function Oxygenases,
pubmed-meshheading:681348-Phenobarbital,
pubmed-meshheading:681348-Rats,
pubmed-meshheading:681348-Selenium
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pubmed:year |
1978
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pubmed:articleTitle |
Rapid stimulation of hepatic microsomal heme oxygenase in selenium-deficient rats. An effect of phenobarbital.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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