Methylation of DNA in target and non-target organs of the rat with methylbenzylnitrosamine and dimethylnitrosamine
- 15 May 1979
- journal article
- research article
- Published by Wiley in International Journal of Cancer
- Vol. 23 (5) , 679-682
- https://doi.org/10.1002/ijc.2910230514
Abstract
The sites of labelling of DNA with [14C]methyl groups from methylbenzylnitrosamine and dimethylnitrosamine were studied in rat oeso-phageal epithelium and liver. All four combinations of tissue and carcinogen were studied. Tissues were labelled in vitro and the DNA contained therein purified and hydrolysed (pH 1, 37° C) to free purines and apurinic acid. Quantitative analysis was performed with the aid of thin-layer chromatography. The apurinic acid and 7-methylguanine fractions were found to be extensively labelled. Smaller amounts of radioactivity were found in O6-methyl-guanine and some of the methylated adenines. The same carcinogen produced different patterns of labelling in oesophageal and liver DNA. The proportion of O6-methylguanine to 7-methylguanine was higher when the methylating agent was a carcinogen specific for the organ.This publication has 18 references indexed in Scilit:
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