Tumors in F344 rats by oral administration of 1,3-diethyltriazene.

A group of 20 male F344 rats was given by gavage a solution of 2.5 mg of 1,3-diethyltriazene in 0.2 ml corn oil twice a week for 20 weeks. Diethyltriazene is very unstable in hydroxylic solvents, but when administered in oil by gavage it induced tumors in almost all of the treated animals, 16 of which had neoplasms of the forestomach; 13 of which were carcinomas. In addition 9 rats had adenomas of the nasal mucosa, two had alveolar-bronchiolar adenomas of the lung, one had a carcinoma of the esophagus and one an adenocarcinoma of the ileum. Half of the rats had died by week 56 of the experiment, the first at week 40 and the last at week 73. The induction of tumors at sites distant from the stomach indicate that diethyltriazene is more stable in the body than would be predicted from its chemical behavior. Although diethyltriazene is a protected alkyldiazonium ion, its carcinogenic effects in rats differ from ethylnitrosoureas, which are also ethylating agents.