In vivo alkylation studies with dichlorvos at practical use concentrations

In vivo covalent binding of organic chemicals to DNA as a quantitative indicator in the process of chemical carcinogenesis

“…The effect is most pronounced with compounds where small metabolites can carry the radioactive Iabel, as with methylating and ethylating agents. With the pesticide dichlorvos, för instance, all radioactivity found in the DN A of rats treated with methyl-labelled chemical was found to be incorporated biosynthetically and not a result of direct methylation [289]. This finding does not, of course, exclude a methylating potential of dichlorvos in vitro [137], but it shows that, at the given dose, the pesticide did not reach the mammalian DNA as an alkylating agent.…”

Changes in DNA properties due to treatment with the pesticides malathion and DDVP

“…It is possible that guanine alkylation by DDVP [ 10,29,30] leads to the formation of single-stranded regions in the vicinity of this residue similarly to the reaction of N-acetoxy-N-2-acetylaminofluorens [7,8]. From numerous papers, e.g.…”

“…eoli and HeLa cells with DDVP the nucleotide bases in DNA are methylated [10,29,30], 7-met-G being the main product of methylation. Other sites, characterized by nu-0301-634X/80/0018/0065/$ 01.80 cleophilic centres, such as phosphoric groups and hydroxy groups of deoxyribose, are also subject to alkylation.…”

Opinion of the Scientific Panel on Plant protection products and their residues (PPR) related to the evaluation of dichlorvos in the context of Council Directive 91/414/EEC

“…The PPR panel identified four (three older and one from 1999) published papers on in vivo alkylation of dichlorvos (Wennerberg and Löfroth, 1974;Wooder et al, 1977;Segerbäck, 1981;Pletsa et al, 1999a). In this experiment the 7-methylguanine fraction in urine collected over 48 hours was 10 x 10 -5 to 14 x 10 -5 of the total radioactivity (dose) applied and thus was three to four times higher than after i.p.…”