Linked Life Data

9641260

Source:http://linkedlifedata.com/resource/pubmed/id/9641260

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1999-3-29
pubmed:abstractText
Peroxisome proliferators are a group of non-genotoxic hepatic carcinogens which have been proposed to act by increasing oxidative damage in the liver. To test this hypothesis, we have produced a transgenic mouse line that has elevated catalase activity specifically in the liver. In this study, we have examined if catalase overexpression influences the induction of lipid peroxidation or oxidative DNA damage, two mechanisms which have been hypothesized to be important in the carcinogenesis by peroxisome proliferators. Transgenic mice or non-transgenic litter mates were fed either 0.01% ciprofibrate or a control diet for 21 days. The activities of fatty acyl CoA oxidase and lauric acid hydroxylase were not significantly affected by catalase overexpression, although the ratio of fatty acyl CoA oxidase to catalase was significantly decreased in transgenic animals. Hepatic lipid peroxidation was estimated by quantifying the concentrations of malondialdehyde and conjugated dienes. Ciprofibrate treatment did not affect either endpoint, but catalase overexpression increased the concentrations of malondialdehyde (in untreated mice only) and conjugated dienes (in both untreated and ciprofibrate-fed mice). Oxidative DNA damage was estimated by quantifying 8-hydroxydeoxyguanosine (8-OHdG) by high-performance liquid chromatography/electrochemical detection. Ciprofibrate treatment significantly increased hepatic 8-OHdG concentrations, in agreement with several previous studies, but catalase overexpression did not significantly affect them, although 8-OHdG concentrations were decreased 50% in untreated mice. These results imply that the metabolism of hydrogen peroxide by catalase is not an important factor in the development of hepatic lipid peroxidation. The decrease in hepatic 8-OHdG in untreated transgenic mice and the increase seen after ciprofibrate administration imply that hydrogen peroxide is important in the formation of 8-OHdG. While the lack of decreased 8-OHdG levels in ciprofibrate-treated transgenic mice does not support this conclusion, it is possible that catalase levels were not sufficiently high to affect this endpoint. Transgenic mice with higher hepatic catalase activities may be required to resolve this issue.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1430-6
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Effect of the peroxisome proliferator ciprofibrate on lipid peroxidation and 8-hydroxydeoxyguanosine formation in transgenic mice with elevated hepatic catalase activity.
pubmed:affiliation
Graduate Center for Toxicology, University of Kentucky, Lexington 40506-0054, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't