Species Specificity in Nitrosamine Carcinogenesis

Many types of carcinogens show pronounced differences in effect in different species, often inducing tumors of a certain site in one and being inactive in another. N-Nitroso compounds, on the other hand, are commonly carcinogenic in all species examined, but induce tumors of different cell types and in different organs from one species to the next. This variability is particularly true of nitrosamines, whose organ and species specificity are probably due to differences in routes of metabolism and activation. These differences are open to study using biochemical and chemical methods and should afford a means of approaching an understanding of the mechanisms of nitrosamine carcinogenesis.