A rat model for studying colonic cancer: Effect of cholestyramine on induced tumors

This is the authors' abstract. We don't add key points for this paper.

Summary Dimethylhydrazine, azoxymethane, and methylazoxymethanol are highly efficient intestinal carcinogens in the rat. Azoxymethane is the best, producing tumors in all rats. The lesions occurred in significant numbers in the small intestine when given at high dosage levels over a period of six months or more. The tumors tend to occur more in the proximal halves of both segments of the intestine. When the animals are fed a 2 per cent cholestyramine diet, there is a marked increase in the tumor yield and the increase is, for the most part, in the large intestine, especially its distal half. Investigations of the mechanisms whereby cholestyramine enhances tumor formation in the large intestine of the rat are continuing. We conclude that the rat given azoxymethane subcutaneously at weekly intervals while on a 2 per cent cholestyramine diet is an excellent experimental model for studies of colonic cancer.