REFINED CARBOHYDRATE ENHANCEMENT OF ABERRANT CRYPT FOCI (ACF) IN RAT COLON INDUCED BY THE FOOD-BORNE CARCINOGEN 2-AMINO-3-METHYL-IMIDAZO[4,5-F]QUINOLINE (IQ)

The aberrant crypt foci (ACF) bioassay has been used extensively to st udy the early effects of different dietary components on the colonic m ucosa of laboratory rodents. ACF are proposed to represent preneoplast ic lesions of colon cancer. Compared to the normally used initiators 1 ,2-dimethylhydrazine dihydrochloride (DMH) and azoxymethane (AOM), the use of a diet-related colon cancer initiator, such as the heterocycli c amine 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ) formed during me at cooking, would probably give a more relevant insight into diet-rela ted colon carcinogenesis. In the present study it is shown that a feed ing regimen with continuous low IQ doses (0.03% in the diet) throughou t a study period of 10 weeks has a significant effect on the induction of ACF in the colon of male F344 rats. In addition, the study illustr ates that the incidence of the IQ-induced ACF can be modulated by the amount of refined carbohydrates in the diet. Rats given a high sucrose /dextrin diet showed a significantly higher number of ACF compared to rats given a diet high in starches. The effect on tumor outcome will a wait the termination of a ongoing parallel study.