Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1985-6-11
pubmed:abstractText
The present paper describes a marked induction of liver microsomal cytochrome P-450 and cytosolic DT-diaphorase to cause possible disorder of steroid homeostasis and promotion of carcinogenicity of 4-nitroquinoline N-oxide (4-NQO) in rats by pretreatment with 3,4,5,3',4'-pentachlorobiphenyl (PenCB) or 2,3,4,7,8-pentachlorodibenzofuran (PenCDF). The animals were sacrificed 5 days after the pretreatment. These induction experiments showed that 7 alpha-hydroxylation of both progesterone and testosterone in liver microsomes was selectively increased to a great extent, but hydroxylations at the 2 alpha-, 6 beta- and 16 alpha-positions were depressed, together with 5 alpha-reduction. From the same microsomes, three of the strongly induced P-450 isozymes, i.e., high- and low-spin P-448s and P-452, were purified. The last isozyme was most responsible for 7 alpha-hydroxylation of testosterone. The pretreatment, also increased activity of DT-diaphorase and reduction of 4-NQO about 10-fold in liver 9000g supernatants. This reduction of 4-NQO was solely catalyzed by DT-diaphorase and the only product was 4-hydroxylaminoquinoline N-oxide, a proximate carcinogen, indicating that the pretreatment strongly increased production of a proximate carcinogen from 4-NQO. Such an enhancement of the metabolic activation of 4-NQO by the pretreatment was also observed to some extent in the lung and the skin. Persistency of PenCB and PenCDF in the liver of rats was also discussed.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-110191, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-113322, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-13428781, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-13890666, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-14907713, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-17539070, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-418889, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-426869, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-4288552, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-4367881, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-524378, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-5850748, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-6411563, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-6772643, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-6818356, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-6820042, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-6820382, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-7268781, http://linkedlifedata.com/resource/pubmed/commentcorrection/3921354-80314
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0091-6765
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
113-9
pubmed:dateRevised
2010-9-13
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Inductive effect on hepatic enzymes and toxicity of congeners of PCBs and PCDFs.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't