Induction of Tumors in the Syrian Hamster with Tumors of the liver, kidneys, and lungs have been induced in rats by the feeding of dimethyl nitrosamine (DMN) and diethylnitrosamine

Tumors of the liver, kidneys, and lungs have been induced in rats by the feeding of dimethyl nitrosamine (DMN) and diethylnitrosamine (DENA) (1, 11, 12, 18). Dontenwill et al. (3, 4) reported that squamous-cell carcinoma of the trachea and lung of Syrian hamsters followed ad ministration of DENA by each of three ap proaches—tube feeding, inhalation, and subcu taneous injection. They observed cirrhosis of the liver but no hepatic cancer. The tumors of the trachea described by Don tenwill and Mohr histologically resemble the squamous-cell papillomas of the trachea and bronchi induced by us following the intratracheal instillation of benzo[a]pyrene suspended in Tween 60 (9). The experiments reported in the present study were designed to compare tumors of the respiratory system that were induced by DENA with similar tumors induced by benzo[a}pyrene in our earlier experiment.