Haloacetonitrile Excretion as Thiocyanate and Inhibition of Dimethylnitrosamine Demethylase: A Proposed Metabolic Scheme

摘要

Haloacetonitriles, contaminants present in chlorinated drinking water, were administered orally to rats and the urinary excretion of thiocyanate was measured as an index of cyanide release. The urinary excretion of thiocyanate accounted for 14.2% of the dose of monochloroacetonitrile; 7.7 to 12.8% of the dose of bromochloro-, dichloro- and dibromoacetonitrile and 2.25% of the dose of trichloroacetonitrile. The haloacetonitriles inhibited rat liver microsomal dimethylnitrosamine (DMN) demethylase in an in vitro assay system. The relative capacity of the haloacetonitriles to inhibit DMN demethylase and to be excreted as thiocyanate did not correlate.