The Effect of Dietary 2-Acetylaminofluorene on the Uracil degrading Enzymes in Rat Liver1

aminofluorene for 90 days have a 10-fold increased capac ity to incorporate uracil into the ribonucleic acids in vivo (2, 16). According to current views (1, 6), the incorpora tion is determined by the activity of the anabolic as well as the catabolic enzyme systems involved in uradil metabo lism. The increased incorporation of uracil might thus be due, at least in part, to a decreased capacity of the liver to degrade the compound. In order to shed light on the mechanism underlying the increased uracil utilization, it was of interest to study the activity of the uracil-degrad ing system in the precancerous liver. The present work is concerned with the effect of dietary 2-acetylaminofluo rene on the activities of the 3 uracil-degrading enzymes, uradil reductase, dihydrouracil hydrolase, and carbamoyl @-alaninehydrolase.