Linked Life Data

9744571

Source:http://linkedlifedata.com/resource/pubmed/id/9744571

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-10-2
pubmed:abstractText
The 2-nitroimidazoles have been used clinically to radiosensitize resistant hypoxic cells, but a dose-limiting peripheral neuropathy has restricted their therapeutic effectiveness. A model compound, 1-methyl-2-nitroimidazole (INO2), was used to investigate the possible role of oxidative stress in this normal tissue toxicity. Chinese hamster ovary (CHO) cells were 10-15 times more resistant to 20 mM INO2 under aerobic than hypoxic conditions. In comparison, a pair of transformed rat embryo fibroblasts (ER17-1wtp53 and ER12L5mtpP53), differing in their p53 genotype, were approximately 3- to 4-fold more sensitive than Chinese hamster ovary cells to INO2 under aerobic conditions, but had the same sensitivity as Chinese hamster ovary cells under hypoxic conditions. These results are consistent with an earlier hypothesis that the mechanism of aerobic toxicity is different from that of hypoxic toxicity (nitroreduction) and show that neither toxicity is dependent on cellular p53 status. There was an increase in the production of reactive oxygen intermediates and a decrease in the antioxidant glutathione following aerobic exposure to INO2, which correlated with cell survival in all three cell lines. No evidence of reductive adducts of the 2-nitroimidazole 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetam ide (EF5) was found by immunofluorescent techniques in aerobic cells. Differing activities of the antioxidant enzymes superoxide dismutase and catalase could be correlated with INO2 aerobic cytotoxicity. DNA strand breaks, as measured by the comet assay, paralleled the appearance of INO2 aerobic cytotoxicity in all three cell lines. Taken together, these results strongly support the conclusion that the aerobic toxicity of IN02 is due to active oxygen species created by futile redox cycling of the parent compound.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
335-44
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Oxidative stress and 1-methyl-2-nitroimidazole cytotoxicity.
pubmed:affiliation
Department of Medical Biophysics, University of Toronto, Ontario, Canada. christine.brezden@utoronto.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't