Induction of colorectal adenocarcinoma in rats by amylopectin sulfate

The carcinogenicity of orally administered amylopectin sulfate was studied in F344 rats. Amylopectin sulfate induced adenomas and adenocarcinomas in the rat colorectum. The incidences of tumor induction in groups that were given a 5% diet of amylopectin sulfate for 3, 6 and 9 months were 2 out of 20 rats (10%), 9 out of 20 rats (45%) and 12 out of 20 rats (60%), respectively. Squamous metaplasia of the colorectum persisted in all rats and progressed irreversibly. Amylopectin sulfate was deposited in the colorectal lamina propria, submucosa and regional lymph nodes. Amylopectin sulfate induced a lesion similar to that produced by degraded carrageenan in the rat colorectum.