Carcinogenicity of N-nitrosoephedrine in rats

N-nitrosoephedrine was administered orally to 32 male Srague--Dawley rats at doses of 120 mg/kg body wt. twice weekly. Of the treated animals, 50% died with preneoplastic and malignant lesions mainly in the liver, lung and forestomach. The median time of death of tumor bearing animals was 522 days after the beginning of the experiment. The observation of hyperkeratosis, papillomas, and 1 squamous cell carcinoma of the forestomach suggests that the compound not only exhibits systemic effects but is probably also a weak local carcinogen.