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Studies on the relationship between dimethyl-nitrosamine-demethylase activity and dimethyl-nitrosamine dependent mutagenesis in, drosophila melanogaster

1983; Elsevier BV; Volume: 46; Issue: 1 Linguagem: Inglês

10.1016/0009-2797(83)90006-6

1872-7786

L.C. Waters, C.R. Nix, J.L. Epler,

Glutathione Transferases and Polymorphisms

The relationship between dimethylnitrosamine (DMN) demethylase activity and DMN-induccd mutagenesis was investigated in Drosophila metanogaster. The activity of DMN-demethylase was at least 10-fold greater in the Hikone-R strain than in three other Drosophila strains. However, the sex-linked recessive lethal (SLRL) mutations induced by DMN in the four strains differed by less than 2-fold. Several possibilities to explain the lack of correlation between DMN-demethylase activity and DMN-induced mutations were tested and eliminated. They include: (i) the presence of inhibitors of DMN-demethylase in extracts of low-activity strains, (ii) a sex bias in the Hikone-R strain in which the enzyme activity is confined to the females, (iii) the possibility that DMN treatment induces DMN-demethylase activity in the low-activity strains and (iv) the possibility that Hikone-R has a much more efficient DNA repair system than the other strains. The results are discussed in terms of what is known about the role of DMN-demethylase in the metabolic activation of DMN in other systems.