Enhancing effect of dextran sulfate sodium on colorectal carcinogenesis by 1,2-dimethylhydrazine in rats.

Four groups were used, each consisting of 24 male ACI rats. Group I received a single subcutaneous injection of 20 mg 1,2-dimethylhydrazine (DMH)/kg body weight and was fed on basal diet until the termination of the experiment. Group II received the same single injection as in group I and then, starting one week later, was fed the diet containing 1% dextran sulfate sodium (DS-M-1). Group III received an injection of 0.9% sodium chloride and then DS-M-1 diet. The control group was given neither DMH nor DS-M-1 diet. The experiment was terminated after 40 weeks. A significantly higher incidence of colorectal carcinoma was observed in group II, as compared with group I (P less than 0.02). These data demonstrate the enhancing effect of DS-M-1 on colorectal carcinogenesis.