Linked Life Data

11551513

Source:http://linkedlifedata.com/resource/pubmed/id/11551513

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-9-11
pubmed:abstractText
Oxazepam (OX), a widely used benzodiazepine anxiolytic, phenobarbital (PHE), a drug used for convulsive disorders, and Wyeth 14,643 (WY; [4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio]acetic acid), a hypolipidemic agent, are all hepatocarcinogenic in B6C3F1 mice. They have been classified as "non-genotoxic" carcinogens since they are non-DNA reactive in in vitro assays and are either negative or weakly positive in Salmonella typhimurium (Ames assay). Male B6C3F1 Big Blue(R) transgenic mice were fed 2500 ppm of OX or PHE or 500 ppm of WY in their diet, while a control group of mice received diet alone for 180 days. The mutant frequency (MF) of cII in the control mice, after correction for clonality, was 6.2 +/- 2.8 x 10(-5). The MF values for mice fed OX, PHE, and WY were 10.0 +/- 3.6 x 10(-5) (P < 0.05), 7.9 +/- 1.3 x 10(-5) (P = 0.1) and 17.4 +/- 4.2 x 10(-5) (P < 0.01), respectively. The mutation spectrum (MS) at cII from the PHE-fed mice was significantly different (P < 0.05) from that of the control mice even though the MF was not, whereas the MS spectra of mice fed OX (P = 0.4) and WY (P = 0.7) were not significantly different. The PHE-derived spectrum differed from the spontaneous spectrum in the lower occurrence of G:C>C:G transversions (17 vs 1.6%) and the higher incidence of A:T>T:A transversions (3.4 vs 9.5%). Prior to correction for clonal expansion, each treated group exhibited a high incidence of frameshift mutations at the homopolymeric run of guanines at bp 179-184 (OX 21%, PHE 21%, WY 16% of the total mutations); this was not the case with the control group (6%). Even after clonal correction, more than 10% of the mutations were frameshifts in the treated mice, while 5% were frameshifts in the control mice. Despite this hypersensitive region of the gene, our findings suggest that the cII locus is less sensitive than the lacI locus to mutation induction by non-DNA reactive carcinogens.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
685-92
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Comparison of the mutant frequencies and mutation spectra of three non-genotoxic carcinogens, oxazepam, phenobarbital, and Wyeth 14,643, at the lambdacII locus in Big Blue transgenic mice.
pubmed:affiliation
Institute for Environmental Studies, Louisiana State University, Baton Rouge, LA, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.