The hepatic conversion of some heterocyclic amines to bacterial mutagens is modified by dietary fat and cholesterol

Groups of Sprague—Dawley rats were fed on diets containingincreasing amounts of beef dripping, but having a constant cholesterolcontent. One group of rats was fed on a diet containing no drippingand no added cholesterol (control). We have studied the abilityof individual hepatic S9 preparations to activate the cookedfood mutagens 2-amino-3-methylimidazo4, 5-f]quinoline (IQ),2-amino-3, 4-dimethyl-imidazo4, 5-f]quinoline (MeIQ) and 2-amino-3,8-dimethyl-imidazo4, 5-f]quinoxaline (MeIQ_x) to bacterial mutagensusing Salmonella typhimurium TA98 as indicator. Hepatic preparationsfrom animals fed on a high cholesterol, low-fat diet were lesseffective in activating the mutagens than preparations fromrats fed on the control diet. It was also observed that thecapacity of hepatic preparations to activate these mutagensincreased as the amount of dripping in the diet increased. Theseresults suggest that it is the triglyceride rather than thecholesterol content of beef dripping which promotes increasedmutagen activation capacity in the liver. ¹To whom correspondence should be addressed