Carcinogenicity study of a commercial sodium oleate in Fischer rats

Sodium oleate was added to the drinking-water of groups of 50 male and 50 female F344 rats at levels of 2.5 and 5.0% for 108 wk. The mean liver weight in males given 5% oleate was lower than that of the males given 2.5% oleate or distilled water alone. The mean thymus weight of females given 5% oleate was higher than that of females given 2.5% oleate or distilled water. There were no statistically significant differences between treated and control rats in the results of the urine and serum analyses or haematological determinations or in the incidence of tumours, apart from pancreatic tumours. The latter, in the males, showed some increase over the concurrent controls but did not differ significantly from the reported spontaneous incidence in this strain. It was concluded that sodium oleate does not induce tumours when given orally to F344 rats.