Selective induction of nasal cavity tumors in rats by diallylnitrosamine.

Weekly intragastric administration of 20, 40, and 80 mg/kg body weight diallylnitrosamine to BD IX rats selectively induced nasal and paranasal cavity tumors with incidences of 30%, 85%, and 65% in females and of 0%, 75%, and 80% in males, respectively. All tumors were carcinomas of the olfactory region, and 95% were invasive. Only a few papillomas in the anterior region were found simultaneously with the carcinomas.