[Carcinogenicity in BD-IX rats of 7 homologues of N-nitroso-N-n-alkylureas in different stages of postnatal development (author's transl)].

Carcinogenic activity of seven N-Nitroso-N-n-alkylureas was investigated in 679 BD-IX rates in different stages of postnatal development after administration of a single s.c. dose of the test compound. The results are compared with a former investigation using N-nitroso-N-ethylurea. The nitrosoureas in a series from the methyl- to the n-octyl derivative showed a pronounced neurotropic carcinogenic effect on treatment during the first ten days after birth. Malignant neurinomas of the heart, subcutaneous sarcomas at the site of injection and malignant tumors in other organs varied distinctly, depending mainly on the time of treatment. All observed effects were similar in all 7 alkylnitrosoureas investigated.