• 1 January 1981
    • journal article
    • research article
    • Vol. 41  (4) , 1363-1367
Abstract
The effect of dietary fat and intestinal microflora on colon and small intestinal carcinogenesis was studied in weanling male F344 germfree and conventional rats fed semipurified diets containing low and high fat. At 7 wk of age, all animals, except vehicle-treated groups, received weekly s.c. injections of 50 mg 3,2-dimethyl-4-aminobiphenyl (DMAB)/kg body weight for 20 wk. The DMAB- and vehicle-treated germfree and conventional rats fed high- and low-fat diets were autopsied 20 wk after the last injection of DMAB. The incidence of colon, small intestinal, ear duct and skin tumors was lower in germfree rats than in the conventional animals. The incidence and multiplicity of DMAB-induced colon tumors were higher in conventional rats fed the high-fat diet than in the conventional animals fed the low-fat diet; the tumor incidence did not differ significantly between the high- and low-fat-fed germ-free animals. Dietary fat had no effect on the incidence of small intestinal tumors in germfree and conventional rats.