[The carcinogenic activity of N-nitrosodipropylamine administered perorally to C57Bl mice].

187 female and male C57B1 mice received N-nitrosodipropylamine (NDPA) twice a week for 50 weeks by intragastric intubation. The total dose of NDPA administered to groups I and II was 3 mg or 1 mg per mouse. The main kinds of tumours in these groups were tumours of esophagus, forestomach, lungs, and lymphomas. The incidence of pulmonary adenomas and forestomach papillomas was more frequent in the group which received a higher dose of carcinogen.