Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2002-8-8
pubmed:abstractText
Previous in vitro studies demonstrated that the rat esophageal carcinogen N-nitrosomethylbenzylamine (NMBA) is metabolically activated by cytochrome P-450s (CYP) 2A3 and 2E1. However, the in vivo role of these P-450s in the metabolism of NMBA has not been fully evaluated. In this study, the effects of single and multiple doses of NMBA were investigated on CYP2A3 and CYP2E1 mRNA expression in the rat esophagus and lung. Seven- to 8-wk old male Fischer 344 rats were administered a single subcutaneous dose of NMBA at either 0.5 mg/kg or 2 mg/kg body weight, after which the rats were sacrificed at 1, 3, 6, 12, 24, 48, and 72 h. In the multiple-dose experiment, 2 groups of rats were dosed with 0.5 mg/kg body weight NMBA 3 times per week for 1 wk or 3 wk. The animals were sacrificed 24 h following the last treatment. Semiquantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis demonstrated a reduction of CYP2A3 mRNA expression in lung and esophagus from NMBA-treated animals compared to dimethyl sulfoxide (DMSO)-treated vehicle controls. This reduction in CYP2A3 mRNA was significant at 48 h in the esophagus and at 24 and 48 h in the lung following a single dose of 2 mg/kg body weight NMBA. In contrast, CYP2E1 mRNA expression remained unchanged in rat lung following NMBA treatment and no consistent pattern of expression could be observed in the esophagus. In the multiple-dose study, a 32% and 25% reduction in esophageal CYP2A3 mRNA expression was observed at 1 and 3 wk, respectively. Similar reductions in CYP2A3 mRNA expression were also observed in the lung. Further, esophageal explants derived from animals pretreated with NMBA in vivo demonstrated a reduced ability to metabolize the carcinogen in vitro as compared to explants from vehicle control animals. Taken together, these data provide further support for a potential role of CYP2A3 in NMBA metabolism in the rat esophagus. Data suggest that CYP2A3 levels in the rat esophagus can be a determinant of its ability to metabolize this carcinogen in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Anticoagulants, http://linkedlifedata.com/resource/pubmed/chemical/Aryl Hydrocarbon Hydroxylases, http://linkedlifedata.com/resource/pubmed/chemical/Carcinogens, http://linkedlifedata.com/resource/pubmed/chemical/Coumarins, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP2E1, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System, http://linkedlifedata.com/resource/pubmed/chemical/Dimethylnitrosamine, http://linkedlifedata.com/resource/pubmed/chemical/Mixed Function Oxygenases, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/coumarin, http://linkedlifedata.com/resource/pubmed/chemical/coumarin 7-hydroxylase, http://linkedlifedata.com/resource/pubmed/chemical/nitrosobenzylmethylamine
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1528-7394
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1077-91
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12167220-Animals, pubmed-meshheading:12167220-Anticoagulants, pubmed-meshheading:12167220-Aryl Hydrocarbon Hydroxylases, pubmed-meshheading:12167220-Biotransformation, pubmed-meshheading:12167220-Carcinogens, pubmed-meshheading:12167220-Coumarins, pubmed-meshheading:12167220-Cytochrome P-450 CYP2E1, pubmed-meshheading:12167220-Cytochrome P-450 Enzyme System, pubmed-meshheading:12167220-Dimethylnitrosamine, pubmed-meshheading:12167220-Esophagus, pubmed-meshheading:12167220-Lung, pubmed-meshheading:12167220-Male, pubmed-meshheading:12167220-Mixed Function Oxygenases, pubmed-meshheading:12167220-Organ Culture Techniques, pubmed-meshheading:12167220-RNA, Messenger, pubmed-meshheading:12167220-Rats, pubmed-meshheading:12167220-Rats, Inbred F344, pubmed-meshheading:12167220-Reverse Transcriptase Polymerase Chain Reaction
pubmed:year
2002
pubmed:articleTitle
Functional role of cytochrome p-450 2a3 in N-nitrosomethylbenzylamine metabolism in rat esophagus.
pubmed:affiliation
Department of Periodontics, Prevention, and Geriatrics, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.