Linked Life Data

8118934

Source:http://linkedlifedata.com/resource/pubmed/id/8118934

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1994-4-7
pubmed:abstractText
Carcinogenic aromatic amines such as 4-aminobiphenyl (4-ABP) are extensively metabolized by both oxidative and conjugation reactions. Thus the burden of genotoxic metabolites of 4-ABP in a target organ is probably influenced by the balance of N-hydroxylation and alternative metabolic pathways in the hepatocyte. In freshly isolated rat hepatocytes, 4-ABP (at a substrate concentration of 10 microM) was mainly N-acetylated (54% of total metabolites), while 2% N-hydroxy-4-ABP-N-glucuronide and 21% of unconjugated N-hydroxylated metabolites were detectable. Ring-hydroxylated metabolites and the primary N-glucuronide of 4-ABP accounted for 8% and 4%, respectively. Pretreatment of rats with 3-methylcholanthrene (MC), a dioxin-type inducer of CYP1A isozymes and phenol UDP-glucuronosyltransferase (UGT1A1), led to a dramatic decrease of N-acetylated (2% of total metabolites) and an increase of N-hydroxylated (54% as free and glucuronidated compound) and ring-hydroxylated (35%) metabolites. Essentially similar effects were seen at a substrate concentration of 50 microM. Consistently, MC-type induction with beta-naphthoflavone resulted in a significant increase in the formation of DNA adducts of 4-ABP, detected by 32P-postlabeling of hepatocellular DNA. The results suggest that, similar to a previous study with 2-naphthylamine (2-NA), MC treatment leads to a marked shift from conjugation to N-oxidation. However, N-hydroxy-4-ABP (in contrast to N-hydroxy-2-NA) is mostly released from hepatocytes in the unconjugated form.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
489-94
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Consequences of 3-methylcholanthrene-type induction for the metabolism of 4-aminobiphenyl in isolated rat hepatocytes.
pubmed:affiliation
Institute of Toxicology, University of Tübingen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't