Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-11-14
pubmed:abstractText
Chronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been shown to lead to the development of hepatotoxicity and carcinogenicity in the liver of female rats. In this study, we investigated hepatic gene downregulation in response to acute and subchronic TCDD exposure. We identified 61 probes which exhibited a downregulation of twofold or greater following subchronic (13 weeks) exposure to TCDD. Comparative analysis of the hepatic expression of these 61 probes was conducted with rats subchronically exposed to PeCDF, PCB126, PCB153, and a mixture of PCB126 and PCB153. PCB153 produced little or no alteration in these probes, while the binary mixture mimicked most closely the downregulation observed with TCDD. To discern if the repression of genes within this probe set occur as a primary response to TCDD exposure, we analyzed the early responsiveness of 11 genes at 6, 24, and 72 h following a single exposure to TCDD. We observed early repression of the 11 genes within this early time course, indicating that the repression of this subset of genes occurs as a primary response to TCDD exposure and not as a secondary response to 13 weeks of subchronic treatment. In addition, the gender, species, and AhR dependence of these responses were also investigated. Gender- and species-dependent repression was observed within this subset of genes. Furthermore, utilizing AhR knockout mice, we were able to determine the AhR-dependent downregulation of seven of 11 genes. Together these results assist efforts to understand the multitude of effects imposed by TCDD and AhR ligands on gene expression.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1096-6080
pubmed:author
pubmed:issnType
Print
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
428-38
pubmed:dateRevised
2010-9-17
pubmed:meshHeading
pubmed-meshheading:16984957-Animals, pubmed-meshheading:16984957-Down-Regulation, pubmed-meshheading:16984957-Environmental Pollutants, pubmed-meshheading:16984957-Female, pubmed-meshheading:16984957-Gene Expression Profiling, pubmed-meshheading:16984957-Gene Expression Regulation, Neoplastic, pubmed-meshheading:16984957-Liver, pubmed-meshheading:16984957-Male, pubmed-meshheading:16984957-Mice, pubmed-meshheading:16984957-Mice, Knockout, pubmed-meshheading:16984957-Oligonucleotide Array Sequence Analysis, pubmed-meshheading:16984957-Polychlorinated Biphenyls, pubmed-meshheading:16984957-RNA, Messenger, pubmed-meshheading:16984957-Rats, pubmed-meshheading:16984957-Rats, Sprague-Dawley, pubmed-meshheading:16984957-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:16984957-Species Specificity, pubmed-meshheading:16984957-Tetrachlorodibenzodioxin
pubmed:year
2006
pubmed:articleTitle
Hepatic gene downregulation following acute and subchronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.
pubmed:affiliation
Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14214, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural