Organotropic effect of N-nitroso-bis-(2-hydroxypropyl)-amine: production of lung adenocarcinoma in rats by a single intraperitoneal injection.

The carcinogenic effect of a single intraperitoneal injection of N-bis(2-hydroxypropyl)nitrosamine (DHPN) was studied in male Wistar rats for 52 weeks. Adenomas were induced in 100% of rats treated with more than 2 g/kg body weight DHPN. Adenocarcinomas were induced in 7%, 25%, 86% and 74% of rats treated with 1, 2, 3 and 4 g/kg body weight, respectively. The labelling index studied by 3H-thymidine autoradiography was 0.33% in normal alveoli, 0.49% in bronchiole, 0.62% in focal cell proliferative area, 1.22% in adenoma, 1.70% in tubular adenocarcinoma and 2.81% in papillary adenocarcinoma. Fewer tumours were induced in the thyroid, kidney and sigmoid colon. Only one pancreatic tumour was observed in a rat treated with 3 g DHPN/kg body weight. These results indicate that, in rats, the lung is the organ most responsive to a single treatment with DHPN.