Methylation of DNAase-digestible DNA and of RNA in chromatin from rats treated with dimethylnitrosamine.
| dc.contributor.author | Galbraith, A | |
| dc.contributor.author | Barker, M | |
| dc.contributor.author | Itzhaki, Ruth F | |
| dc.date.accessioned | 2011-07-20T14:05:02Z | |
| dc.date.available | 2011-07-20T14:05:02Z | |
| dc.date.issued | 1979-02-27 | |
| dc.identifier.citation | Methylation of DNAase-digestible DNA and of RNA in chromatin from rats treated with dimethylnitrosamine. 1979, 561 (2):334-44 Biochim Biophys Acta | en |
| dc.identifier.issn | 0006-3002 | |
| dc.identifier.pmid | 427160 | |
| dc.identifier.uri | http://hdl.handle.net/10541/136429 | |
| dc.description.abstract | After injecting rats with di[14C]methylnitrosamine we have prepared liver chromatin and have examined firstly, the methylation level of the DNAase I-degradable fraction of the DNA and secondly, the level of methylation and the stability of methylated sites in chromatin RNA. Our results show that the level of 7-methylguanine in the degradable DNA is about 1.3 times that of whole DNA; therefore in the 20% or so of the DNA which is undegradable by DNAase I, the level must be very low or zero. Experiments using chromatin from rats injected with unlabelled dimethylnitrosamine plus [3H]thymidine show that the specific activity is similar in the DNAase I degradable and undegradable fractions, suggesting that there is no preferential repair in the latter region. In chromatin RNA, the level of 7-methylguanine is higher than that of whole DNA and decreases fairly rapidly within 30 h after dimethylnitrosamine treatment. Our results indicate that this decrease is due to some type of excision or repair process rather than to normal turnover. | |
| dc.language.iso | en | en |
| dc.subject.mesh | Animals | |
| dc.subject.mesh | Cell Nucleus | |
| dc.subject.mesh | Chromatin | |
| dc.subject.mesh | DNA | |
| dc.subject.mesh | Deoxyribonucleases | |
| dc.subject.mesh | Dimethylnitrosamine | |
| dc.subject.mesh | Liver | |
| dc.subject.mesh | Male | |
| dc.subject.mesh | Methylation | |
| dc.subject.mesh | Nitrosamines | |
| dc.subject.mesh | RNA | |
| dc.subject.mesh | Rats | |
| dc.title | Methylation of DNAase-digestible DNA and of RNA in chromatin from rats treated with dimethylnitrosamine. | en |
| dc.type | Article | en |
| dc.identifier.journal | Biochimica et Biophysica Acta | en |
| html.description.abstract | After injecting rats with di[14C]methylnitrosamine we have prepared liver chromatin and have examined firstly, the methylation level of the DNAase I-degradable fraction of the DNA and secondly, the level of methylation and the stability of methylated sites in chromatin RNA. Our results show that the level of 7-methylguanine in the degradable DNA is about 1.3 times that of whole DNA; therefore in the 20% or so of the DNA which is undegradable by DNAase I, the level must be very low or zero. Experiments using chromatin from rats injected with unlabelled dimethylnitrosamine plus [3H]thymidine show that the specific activity is similar in the DNAase I degradable and undegradable fractions, suggesting that there is no preferential repair in the latter region. In chromatin RNA, the level of 7-methylguanine is higher than that of whole DNA and decreases fairly rapidly within 30 h after dimethylnitrosamine treatment. Our results indicate that this decrease is due to some type of excision or repair process rather than to normal turnover. |