title: The effect of heavy metal ions on the rate of decomposition of N-ethyl-N-nitrosourea and other carcinogenic N-nitrosamides.
abstract: The decomposition of ethylnitrosourea (ENU) in aqueous solution is enhanced by Cu2+ ions. Ni2+ shows a similar, but less pronounced effect. The decomposition rate of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a compound known to be relatively stable in aqueous solution, is strongly enhanced by the addition of Cu2+ and to a smaller extent also by Ni2+ ions. On the other hand the stability of N-methyl-N-nitrosourethane is not influenced by heavy meatal ions. The influence of Cu2+ ions on the decomposition rate of ENU is similar to that of OH-anions, influencing the reaction kinetics on a molar basis. The increase in decomposition rate of ENU by copper ions is not seen in the presence of blood serum or other complexing agents. The results are discussed in relation to the known enhancement in toxicity and carcinogenicity of ENU by heavy metal salts in animal experiments.
mesh_terms: D001769:Blood; D003300:Copper; D004347:Drug Interactions; D004355:Drug Stability; D004492:Edetic Acid; D005038:Ethylnitrosourea; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D008769:Methylnitronitrosoguanidine; D009532:Nickel; D009603:Nitroso Compounds; D009605:Nitrosomethylurethane; D009607:Nitrosourea Compounds; D012996:Solutions; D014867:Water
chemical_list: D009603:Nitroso Compounds; D009607:Nitrosourea Compounds; D012996:Solutions; D014867:Water; D008769:Methylnitronitrosoguanidine; D009605:Nitrosomethylurethane; D003300:Copper; D009532:Nickel; D004492:Edetic Acid; D005038:Ethylnitrosourea