Effects of differing concentrations of sodium butyrate on 1,2-dimethylhydrazine-induced rat intestinal neoplasia

The incidence, distribution, size, and histopathology of small and large bowel tumors induced by parenteral administration of 1,2-dimethylhydrazine were examined in rats given 1% or 2% sodium butyrate dissolved in drinking water. Although previous in vitro reports on colon cancer cell lines have suggested that sodium butyrate might have a role to play as a chemotherapeutic "differentiating agent," the results of this in vivo study indicate that sodium butyrate treatment enhanced the development of colonic neoplasia and was associated with increased fecal butyric acid concentrations. In contrast, no changes were seen in the incidence of small bowel tumors, luminal butyric acid concentrations, mucosal morphology, or brush-border enzyme activities (i.e., sucrase, alkaline phosphatase). This study suggests that dietary butyrate has an important, possibly indirect, regulatory role in carcinogenesis associated with an experimental animal model of colonic neoplasia.