Comparative metabolism of beta-oxidized nitrosamines.

Several beta-oxidized nitrosamines have been shown to induce pancreatic cancer in Syrian hamsters. N-Nitrosobis(2-oxopropyl)amine (ND2OPA) is the most specific, but it also induces either colonic or prostatic tumours in MRC-Wistar rats. In-vivo and in-vitro metabolic studies show that N-nitrosomethyl(2-oxopropyl)amine is a metabolite of ND2OPA in hamsters but not in rats. ND2OPA is also present in higher concentrations in hamster pancreas than in the liver. No similar effect occurs in rats. These factors may explain, in part, the organotropism and species specificity of this nitrosamine.