The early phase of colon tumorigenesis induced by dimethylhydrazine in ICR mice.

In order to study the influence of fiber supplements on dimethylhydrazine induction of colon tumorigenesis six-week-old CD1 (ICR): Crj mice were injected i.m. at a dimethylhydrazine (DMH) dose 10 mg/kg body weight once weekly for 10 weeks with or without dietary supplementation with 3% polydextrose, lactosucrose or cellulose, or 3% polydextrose and 3% cellulose in combination. There were no significant differences in colon tumor induction among the groups. However, microadenomas were observed 10 weeks after the first treatment of DMH so that this protocol may be useful for studies of the early phase of colon carcinogenesis in mice.