Linked Life Data

3087637

Source:http://linkedlifedata.com/resource/pubmed/id/3087637

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-8-14
pubmed:abstractText
The cytochrome P-450 content of nuclear membranes isolated from the livers of male Sprague-Dawley rats fed a semipurified diet containing 0.05% w/w 2-acetylaminofluorene (AAF) for 3 weeks, was only about 20% of the values in control rats fed the same diet devoid of AAF. This effect was apparent after only 1 week of AAF treatment and persisted in nuclear membranes from isolated hyperplastic nodules (HPN) generated by 4 cycles of interrupted AAF-feeding. The microsomal cytochrome P-450 content, on the other hand, remained at control levels after 1 week of AAF treatment, and it was only slightly decreased after 3 weeks. In contrast, microsomes from HPN generated by prolonged AAF treatment had markedly decreased amounts of cytochrome P-450. The AAF treatment also caused changes in cholesterol epoxide hydrolase activity, which paralleled those observed for cytochrome P-450 content. Nuclear membranes from livers of rats fed AAF for 3 weeks, and from isolated HPN, had only 30-50% of the cholesterol epoxide hydrolase activity present in controls, whereas the microsomal enzyme activity remained at control levels after 3 weeks of AAF feeding but was 50% depressed in microsomes from HPN. The selective loss of cytochrome P-450 and of cholesterol epoxide hydrolase in hepatic nuclear membrane, but not in microsomes, of rats fed AAF for 3 weeks suggests independent control for these enzymes in these two membrane fractions. Cytochrome P-450 plays a role both in the activation of AAF (N-hydroxylation) as well as in its detoxification (ring hydroxylation) whereas cholesterol epoxide hydrolase initiates the detoxification of cholesterol epoxide. Therefore, our findings suggest the hypothesis that AAF treatment causes an early loss, at the surface of the nucleus, of the last line of defense for detoxification of transforming or promoting metabolites generated by microsomal activation of natural substances such as cholesterol and of xenobiotics such as AAF.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0009-2797
pubmed:author
pubmed:issnType
Print
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
125-36
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Loss of cytochrome P-450 from hepatic nuclear membranes of rats fed 2-acetylaminofluorene.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't