Herbal Authority

N NITROSOBIS (2 OXOPROPYL) AMINE (NBOP), a postulated 3-metabolite of di-n-propyl-nitrosamine, has been found to be a potent carcinogen in different species of animals (Pour et al., 1977a; Rao & Pour, 1978; Pour et al., 1979). In hamsters, a single or repeated s.c. administration of NBOP (Pour et al., 1977a, 1978) is reported to cause a high incidence of pancreatic ductal tumours. Because of the close histological similarity of hamster pancreatic ductal adenocarcinoma to human pancreatic cancer of ductal origin, this model is felt to be superior to other animal models of pancreatic cancer (Dissin et al., 1975; Longnecker & Curphey, 1975; Reddy & Rao, 1975). However, the hamster model has certain limitations: a protracted mean latent period of 39 weeks for the appearance of pancreatic ductal adenocarcinoma after administration of a single dose of NBOP equivalent to that used in the present study, and the frequent development of neoplasms in sites other than pancreas, such as liver, lungs and nasal turbinates, when multiple doses of carcinogen are administered. We have undertaken the present studies in an attempt to refine this model by studying the carcinogenic effects of limited doses of NBOP in newborn and suckling hamsters. These experiments are based on the observation that newborn animals of different species have been shown to be highly susceptible to the effects of chemical carcinogens (Walters et al., 1967; Toth & Shubik, 1967; Vesselinovitch & MihaloAccepte(d 4 March 1980