title: Methionine-cysteine deficiency and alkylation of DNA in liver, kidney and lung of mice administered dimethylnitrosamine.
abstract: The effect of methionine-cysteine deficiency on the methylation of DNA purines by dimethylnitrosamine metabolites was studied in subadult and adult mice. In liver, no dietary effect on the specific methylation of 7-methylguanine was observed, while that of 3-methyladenine decreased in the adult animals. The specific methylation of guanine in the 0(6)-position and the ratio of 0(6)-methylguanine to 7-methylguanine increased significantly after methionine-cysteine deficiency. Methylation in kidney decreased in subadult but increased in adult mice. In lung, the amount of 7-methylguanine was significantly elevated after methionine-cysteine deficiency in both the subadult and adult mice. The results demonstrate an increase in the specific methylation in liver of guanine in the 0(6)-position by the methionine-cysteine deficient diet, together with differences in the methylation pattern between organs of the two age groups.
mesh_terms: D000375:Aging; D000478:Alkylation; D000818:Animals; D003545:Cysteine / Q000172:deficiency*; D004247:DNA / Q000378:metabolism*; D004032:Diet; D004128:Dimethylnitrosamine / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008715:Methionine / Q000172:deficiency*; D008745:Methylation; D051379:Mice; D011687:Purines / Q000032:analysis
chemical_list: D011687:Purines; D004247:DNA; D008715:Methionine; D003545:Cysteine; D004128:Dimethylnitrosamine