Donald D. Bills

Null carcinogenic effect of large doses of nitrosoproline and nitrosohydroxyproline in Wistar rats.

Summary The nitrosamino acids, nitrosoproline or nitrosohydroxyproline, were given orally to weanling rats in four weekly doses totalling 290 mg/animal and the rats were observed for their lifetime. Negative controls received water and positive controls were given diethylnitrosamine. The rats were maintained on a basal semi-purified diet or a basal diet containing cyclopropenoid fatty acids. No tumorigenic effect was seen in rats given nitrosoproline or nitrosohydroxyproline. Diethylnitrosamine produced a high incidence of hepatomas, as expected. Cyclopropenoid fatty acids had no significant effect on the carcinogenicity of the nitrosamino acids.