Colostomy closure promotes cell proliferation and dimethylhydrazine-induced carcinogenesis in rat distal colon

摘要: The influence of adaptive cell proliferation on colonic carcinogenesis was studied in male Fischer rats with a defunctioning transverse colostomy that closed 4 wk later. Control observations were made other after transection, repeated at wk, laparotomy alone, or permanent colostomy. Tumors induced by 1,2-dimethylhydrazine (total dose, 300 mg/kg) over 11 starting 2 days the second operation. After creation colostomy, amounts protein, RNA, and DNA distal colon halved (p less than 0.001), but returned to normal 7 restoration continuity. This reactive hyperplasia promoted development carcinomas, as compared having transection bowel (incidence 32% vs. 6%; p 0.03). Although protein nucleic acid proximal unchanged values increased 18%-59% closure = 0.05-0.002); nonetheless, yield tumors this segment unaltered. Suture-line cancers commoner repeat (76% 39%; 0.01). These data confirm promotional effect intestinal carcinogenesis.