Nitrosamine Studies: Neoplasms of Liver and Genital Mesothelium in Nitrosopyrrolidine-Treated MRC Rats23

Abstract

Nitrosopyrrolidine, a cyclic nitrosamine, produced hepatocellular carcinoma in 25 of 25 MRC rats when fed for 67 weeks at a total dose of 1,340 mg. The histologic features of these tumors are described and related to their intravascular growth behavior and metastafic tendencies. Genital tumors occurred in 7 of 12 male rats, and 4 of these were papillary mesotheliomas of the tunica vaginalis testis, a histologic type rarely described in this species. A review of the literature with respect to the carcinogenic activity of nitroso compounds and their possible relationship to human neoplasia is presented.