The Metabolism of [¹⁴C-Methyl]Dichlorvos in the Rat and the Mouse

Abstract

1. [¹⁴C-Methyl]-labelled dichlorvos (2,2-dichlorovinyl dimethyl phosphate) was administered orally to rats and mice.

2. Excretion of radioactivity was rapid and similar in both species. The major routes of excretion of radioactivity were the urine (58.8–64.6%) and expired carbon dioxide (14.4–18.5%).

3. Dimethyl phosphate was the major metabolite in both species, indicating that hydrolysis was an important mechanism of detoxication.

4. Demethylation also represented an important route of detoxication. The presence of S-methylcysteine, S-methylcysteine S-oxide and methyl mercapturic acid as minor urinary metabolites indicated that glutathione alkyl transferase action was responsible for at least part of the dealkylation. Hydrolysis and dealkylation may be equally important in the detoxication of dichlorvos.