Carcinogenesis by nitrosamines and azoxyalkanes by different routes of administration to rats.

The effects of administering similar doses of some simple alkylating agents to rats by different regimens have been compared. Two of the compounds were methylating agents, nitrosodimethylamine and azoxymethane; two were ethylating agents, nitrosodiethylamine and azoxyethane; and nitrosomethylethylamine was both a methylating and an ethylating agent. The treatments gave rise to tumors in almost all treated rats. The results indicate the importance of pharmacokinetics in determining which organs are the targets of the alkylating carcinogens.