Abstract
The tumorigenesis and cystic lesion by a single intraperitoneal administration (ip) of N-bis (2-hydroxypropyl) nitrosamine (DHPN) for 52 weeks were studied in ddY mice. The amount of DHPN was 1000 mg/kg in group I, 500 mg/kg in group II, 250 mg/kg in group III, 125 mg/kg in group IV and 0 mg/kg in group V. The tumorigenesis of DHPN was found in the lung and liver. However, cystic lesion was observed only in the liver. Lung tumors were adenoma, adenocarcinoma and squamous cell carcinoma. As liver tumors, adenoma, hepatocellular carcinoma, cholangioma and hemangioma were observed only in the mice treated with DHPN. Incidence of cystic lesion in the liver was detected in all groups treated with DHPN. Histologically, cystic lesion of the liver showed four patterns of bile duct-like, sinusoid-like, hepatocyte-like and mixed.
