Enhancing effect of bile and bile acid on stomach tumorigenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The carcinogenic or cocarcinogenic effects of bile or bile acid on stomach carcinogenesis were investigated in inbred W rats. Bile or bile acid was introduced into the stomach by choledochogastrostomy or with food after the administration of N-methyl-N'-nitro-N-nitrosoguanidine [(MNNG) CAS: 70-25-7; 1-methyl-3-nitro-1-nitrosoguanidine] in drinking water. The animals that received MNNG and bile or sodium taurocholate (CAS: 145-42-6; N-choloyltaurine sodium salt) had a significantly higher incidence of hyperplastic and neoplastic lesions in the stomach mucosa than did the relevant MNNG-treated controls. The result suggested an enhancing effect of bile and sodium taurocholate in stomach tumorigenesis.