INFLUENCE OF DIETARY-FAT ON DNA-BINDING BY 2-AMINO-3,8-DIMETHYLIMIDAZO[4,5-F]QUINOXALINE (MEIQX) IN THE MOUSE-LIVER

Female BALB/c mice were fed either a low (1%)-fat or one of three high -fat diets (containing an additional 25% (w/w) beef fat, hydrogenated vegetable oil or non-hydrogenated vegetable oil) for 4 wk. They were t hen orally treated with 10 mg 2-amino-3,8-dimethylimidazo[4,5-f]quinox aline (MeIQx)/kg body weight and killed 6 hr later. Consumption of the hydrogenated vegetable oil was accompanied by increased DNA adduct fo rmation in mice. The abilities of hepatic S-9 preparations from mice f ed the various diets to convert MeIQx to an active bacterial mutagen w as assessed using Salmonella typhimurium TA98. Preparations from mice fed the high-fat diets exhibited significantly greater capacity to act ivate MeIQx than did those from low-fat-fed mice. The greatest increas es were seen with S-9 from animals fed either beef fat or hydrogenated vegetable oil.