Induction of thyroid follicular adenomas and carcinomas by N-nitrosobis(2-oxopropyl)amine

Subcutaneous injection of N-nitrosobis(2-oxypropyl)amine (BOP) induced thyroid follicular adenomas and carcinomas in MRC rats. The tumor yield was 50% following a single dose and 60% after weekly treatment for life. In males the tumor incidence was slightly higher and the latency period shorter, while in females, the tumors were larger. Sites of origin, size, multiplicity and morphologic patterns of tumors were analyzed in relation to dose and sex. The possible mechanisms involved in tumorigenesis are discussed.