Clonorchis sinensis (CS) infection combined with hepatocarcinogen treatment results in marked cholangiocarcinoma (CC) formation in hamsters. Hamsters were kept for 16 weeks with or without 1% aminoguanidine (AG) exposure through drinking water, and were treated with dimethylnitrosamine for 4 weeks, 2 days after being infected orally with 15 metacercariae of CS. Interestingly, of the 11 hamsters not treated with AG, 9 had malignant tumors, 1 had a benign tumor, and 1 was normal; however, of the 10 hamsters treated with AG, 5 had benign tumors, 4 had malignant tumors, and 1 was normal. Based on this result, AG has an inhibitory effect on the progression of CC. Further mechanistic study into the result of this morphological study is warranted.
2005 The Japanese Society of Toxicologic Pathology