[The role of bile acids with physiological concentration in colon carcinogenesis].

The promoting effect of bile acids in physiological concentration in colon carcinogenesis was studied using male Wistar rats with defunctioned colon. After an instillation of MNNG, collected rat faces (group A), secondary bile acids i.e. deoxycholic acid and lithocholic acid in equal concentration to rat feces (group B) and control material (group C) was instilled in the defunctioned colon. Concerning the incidence and the number of macroscopically visible tumor, no significant difference was found among these three groups. However, the number of histological lesion with atypia in flat mucosa of the colon in group A and B was significantly greater than that in group C. Considering this result and the results obtained from prestudy of kinetics of colonic epithelial cells by the use of anti BrdU monoclonal antibody, feces and physiological concentration of bile acids had a promoting effect in colon carcinogenesis.