Carcinogenicity testing of N-hydroxy and other oxidation and decomposition products of 1- and 2-naphthylamine.

Abstract

Summary N -Hydroxy-2-naphthylamine produced bladder tumors in three of four dogs when administered over a period of 30 months (dogs were sacrificed 15 months later) in dimethyl sulfoxide solution by repeated instillation directly into the bladders. N -Hydroxy-1-naphthylamine was more carcinogenic than N -hydroxy-2-naphthylamine by administration to rats, but the reverse was observed in four experiments with neonatal mice. 2-Amino-1,4-naphthoquinone- N 4 , 2-naphthylimine and dibenzo( a, h )phenazine were tested in neonatal mice and by p.o. administration to dogs. No evidence that these contaminants of 2-naphthylamine were responsible for its carcinogenic action was obtained. A poor correlation between urine cytology and bladder pathology at autopsy was observed in dogs given these carcinogens.