Katherine Stepan

Induction of benign and malignant lip tumors in Syrian hamsters by topical application of N-nitrosobis(2-oxopropyl)amine and N-nitroso(2-hydroxypropyl)(2-oxopropyl)amine

Weekly topical application of equitoxic doses of N-nitrosobis(2-oxopropyl)amine (BOP) or N-nitroso(2-hydroxypropyl)(2-oxopropyl)amine (HPOP) to lip and/or vagina of female Syrian hamsters led to the development of papillomas and carcinomas of the lip, papillomas of the vagina, and tumors of internal organs. The relative incidence of the tumor types is affected by the dose of BOP or HPOP administered. BOP is excreted unchanged and as HPOP in the saliva of Syrian hamsters injected subcutaneously with BOP and pilocarpin. This result may help to explain preliminary observations that subcutaneously injected BOP and pilocarpin also lead to lip tumors.

Carcinogenicity of N-nitrosobis (2-hydroxypropyl) amine after administration to Syrian hamster skin

Weekly application of N-nitrosobis (2-hydroxypropyl) amine (BHP) at a dose of 50 mg/application to the skin of the neck and flank organ of male Syrian golden hamsters induced no local lesions. However, nearly all treated animals developed internal tumors, primarily of pancreatic, hepatic, respiratory and colorectal origins. Results from this and previous studies indicate that the local carcinogenic effect of nitrosamines depends on the molecular structure of the carcinogen, rather than on tissue specificity. Furthermore, some common types of human cancer could be induced by absorption of specific nitrosamines through skin.