Carcinogenesis by oxygenated nitrosomethylpropylamines in Syrian hamsters

Three oxygenated propylnitrosomethylamines were administered to female Syrian hamsters at doses similar to those which had induced high incidences of esophageal neoplasms in rats. Nitrosomethyl-2-oxopropylamine (NMOP) given at the rate of 2 mg/animal/week, whether as one application of 2 mg or two applications of 1 mg, led to early death of the animals, mostly with liver neoplasms; administration of 1 mg/animal/week led to longer survival, but most animals died with both liver neoplasms and neoplasms of the nasal mucosa. Only one hamster treated with NMOP had a neoplasm of the pancreatic duct. Of the 14 hamsters treated with the higher dose of nitrosomethyl-2-hydroxypropylamine (NMHP) and surviving beyond 6 weeks, most had liver neoplasms and nine had neoplasms of the pancreatic ducts. At the lower dose of NMHP, most hamsters developed neoplasms of the nasal mucosa, as did those receiving the same dose of NMOP, and seven animals had hemangioendothelial tumors of the liver, but only one animal had a carcinoma of the pancreatic duct. Nitrosomethyldihydroxypropylamine (NMDHP) was a much weaker carcinogen than the other two compounds and induced mainly neoplasms of the nasal mucosa, with little shortening of life.