The action of rat cytosol enzymes on some methylated nucleic acid components produced by the carcinogenic N-nitroso compounds.
AffiliationPaterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester
MetadataShow full item record
AbstractThe stabilities of several alkylated nucleic acid components have been examined in the presence of cytosol extracts from a variety of rat tissues. An activity capable of demethylating O6-methyldeoxyguanosine was readily detectable in all tissues examined; arranged in approximate order of decreasing specific activity these are as follows: small intestine, spleen, kidney, lung, liver, skin, heart and brain. The in vitro requirements for the activity derived from liver and the observations that O6-methylguanine and its deoxynucleoside 5'-monophosphate are insensitive to the action of these extracts suggests that this activity may be due to an enzyme which resembles adenosine deaminase. In contrast to the ready degradation of O6-methyldeoxyguanosine the corresponding ethyl derivative was degraded very much more slowly but there was no evidence for other activities against the O4- and O2-methyldeoxythymidines. Similarly, no demethylation of the N-substituted deoxynucleosides, 3-methyldeoxycytidine 3-methldeoxythymidine, 1-methyldeoxyadenosine and 7-methyldeoxyguanosine, was detected.
CitationThe action of rat cytosol enzymes on some methylated nucleic acid components produced by the carcinogenic N-nitroso compounds. 1979, 26 (1):91-102 Chem Biol Interact
- Metabolism of O6-alkyldeoxyguanosines and their effect on removal of O6-methylguanine from rat liver DNA.
- Authors: Pegg AE, Swann PF
- Issue date: 1979 Dec 17
- Measurement of O6-methyldeoxyguanosine in DNA methylated by the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone using a biotin-avidin enzyme-linked immunosorbent assay.
- Authors: Foiles PG, Trushin N, Castonguay A
- Issue date: 1985 Jul
- Quantitative determination of N7-methyldeoxyguanosine and O6-methyldeoxyguanosine in DNA by LC-UV-MS-MS.
- Authors: Yang Y, Nikolic D, Swanson SM, van Breemen RB
- Issue date: 2002 Oct 15
- Nitrosamine-induced carcinogenesis. The alklylation of nucleic acids of the rat by N-methyl-N-nitrosourea, dimethylnitrosamine, dimethyl sulphate and methyl methanesulphonate.
- Authors: Swann PF, Magee PN
- Issue date: 1968 Nov
- Formation and persistence of O6-(2-hydroxyethyl)-2' -deoxyguanosine in DNA of various rat tissues following a single dose of N-nitroso-N-(2-hydroxyethyl)urea. An immuno-slot-blot study.
- Authors: Ludeke BI, Kleihues P
- Issue date: 1988 Jan