[Effects of fecal bile acids on experimental colon carcinogenesis]. / Die Wirkung der Fäkalgallensäure auf die experimentelle Kolonkarzinogenese.

Because of the in a controversial way held discussion on an possibly existing connection between bile acid metabolism and the development of colonic carcinomas experimental researches on this problems were carried out with Wistar rats. Two test series with altogether 130 animals manifested independently from each other the result of a provable connection. During model tests small bowel resections and colon exclusion operations were realized. The carcinoma protection was accomplished by 1.2 dimethylhydrazine administered for 14 weeks in a doses of 20 mg/kg body weight. The carcinoma was proved after a 32-weeks-period. It was shown that in case of shortening the ileum more than in case of reduction of the jejunum on the left-side colon adenocarcinomas develop and the amount of the excreted fecal bile acids is the highest one. In bypassing the left-side section of the colon carcinomas develop also on the left side of the colon. But their number is significantly lower than of those on the right side. The test results indicate a causal connection.

Effect of small bowel resection on fecal bile acid excretion and on experimental colon tumour in rats.

Ileal and jejunal resections were carried out to investigate their effect on the faecal bile acid excretion and on the development of 1,2-dimethylhydrazine (DMH)-induced colonic cancer in rats. Both resection types raise the total daily faecal bile acid level compared to the control sham-operated group, whereas ileal resection has a more pronounced effect. The incidence of tumours was found higher in groups with enhanced faecal bile acid level. Our findings show a connection between the daily faecal bile acid excretion and the incidence of DMH-induced colonic cancer.

The extent of bile reflux and development of gastric cancer after resections in rat.

Authors performed gastric resections (Billroth II, Billroth I, Billroth II+, Braun anastomosis and Roux Y reconstruction) and laparotomies in five groups, of 110 Wistar male rats. Thirty-eight weeks postoperatively the surviving 91 animals were sacrificed, and histological study was made of the frequency of gastric stump cancer in the individual groups and the extent of bile reflux characteristic of the individual GEA types was measured. Based on their results, the risk of stump cancer was higher in operation types associated with considerable bile reflux (a cancer incidence rate of 50% after Billroth II, 28.5% after Billroth I). Following gastric resections accompanied by insignificant bile reflux (Billroth II + Braun, Roux Y) the risk of gastric stump cancer was significantly lower.

Effect of change of fecal bile acid excretion achieved by operative procedures on 1,2-dimethylhydrazine-induced colon cancer in rats.

The effect of bile on the development of 1,2-dimethylhydrazine (DMH)-induced colon cancer was studied in male Wistar rats. Experimental operative models were created, in which in Group 1, the half intestinal tract, the ileum, and the right side of colon were released from bile. In Group 2, both sides of the colon contained bile. The sham operated animals formed Group 3. These techniques changed the concentration of bile acid in different parts of the colon, and the daily total fecal bile acid excretion as well. After DMH treatment, the relationship between these changes of bile acid level and the development of colon cancer was studied. Significantly more tumors than in the control group were found if the daily total bile acid level and the bile acid concentration in the left side of the colon were increased. Our findings show an unambiguous connection between the fecal bile acid level and the incidence of DMH-induced colon cancer.

[The role of bile in the development of colon cancer induced by 1,2-dimethyl hydrazine in rats]. / Az epe szerepe az 1,2-dimetilhidrazin-indukálta vastagbéldaganatok kialakulásában, patkányban.

Experimental operative models were created in order to investigate the role of the bile acids in the development of colon cancer in rats. These techniques changed the concentration of bile acids in different parts of the colon, and the daily fecal total bile acid levels. The relationship between these changes and the development of 1,2-dimethylhydrazin-induced colon cancer was studied. Significantly more tumors than in the control group were found if the daily total bile acid level and the concentration of bile acids in the left subsite of the large bowel was increased. Our results suggest that bile acids, as promoting factors, may play a role in the development of colon cancer in rats.