Mouse colostomy model for studies on large bowel cancer.

The development of appropriate animal model systems has been proposed as a means of facilitating the study of human colorectal cancer. This report describes the development and use of a blind-colorectal pouch in a carcinoma mouse model. The blind-pouch was prepared in C57BL/6J mice by surgically exteriorizing the descending colon and producing two stomata in the abdominal wall. The proximal stoma served as an end colostomy and the distal stoma created as a mucous fistula. Surgical closure of the anus thus provided a colorectal pouch. In pilot studies it was found that N-methyl-N-nitrosourea (MNU) and radiation together but neither separately produced tumors in the pouch of surviving mice. Further, inoculation of C38 syngeneic tumor cell suspension into the pouch and immediate closure resulted in tumor takes within three to four weeks. The use of this model in carcinogenesis and the immunology of colon cancer simulate the human colorectal cancer problem more closely than previous animal models.