Vascular tumors of the spleen and other neoplasms induced in Syrian golden hamsters by 1-propyl-1-nitrosourea.

Continuous administration of either 400 ppm or 100 ppm 1-propyl-1-nitrosourea (PNU) in drinking water to Syrian golden hamsters, from 11 weeks of age, induced tumors of the spleen, forestomach, duodenum, and vagina. The tumor incidences in the spleen were 33 of the 36 males (91.7%) and 34 of the 37 females (91.9%) in the 400 ppm group and 32 of the 40 males (80%) and 26 of the 34 females (76.5%) in the 100 ppm group. In addition, tumors were induced in the forestomach and duodenum of both sexes and in the vagina in females. Histologically, the tumors were classified as hemangioendotheliomas of the spleen, squamous cell papillomas and carcinomas of the forestomach, adenocarcinomas of the duodenum, and squamous cell papillomas and carcinomas of the vagina. Compared to results previously reported in rats, the present results reveal a remarkable species difference in the organ specificity of PNU.