Tumorigenic action of N-n-butyl-N-formylhydrazine in mice.

Continuous administration of 0.04% N-n-butyl-N-formylhydrazine (BFH) in drinking water to 6-week-old randomly bred Swiss mice for life produced tumors of the lungs, preputial and clitoral glands. The tumor incidences in these three tissues of the treated animals were 87, 66, and 10%, whereas in the untreated controls they were 25, 0, and 0%, respectively. Histopathologically, the tumors were classified as adenomas and adenocarcinomas of the lungs, squamous cell papillomas and carcinomas, angio-, fibro-, and myxo- sarcomas of preputial glands and squamous cell papillomas and carcinomas of clitoral glands. N-n-Butyl-N-formylhydrazine is a structural homologue of the carcinogenic N-methyl-N-formylhydrazine and N-ethyl-N-formylhydrazine. These studies are integral parts of structure activity relationship inquiries.