The Mechanism of Dietary Alterations in Rat Hepatic Xanthine Oxidase Levels

摘要: Dietary protein depletion results in a decrease rat hepatic xanthine oxidase activity to about 10% of control levels. Refeeding high diet leads, after 6-hour lag phase, 5-fold increase enzyme by 12 hours. The mechanism this was studied utilizing actinomycin D, 5-fluorouracil, and puromycin. These agents all blocked the activity, indicating that both ribonucleic acid syntheses were involved. Following administration 14C-leucine, specific radioactivities identical livers protein-depleted animals, despite 10-fold difference indicated fractional turnover rates same two groups rats suggested rate synthesis reduced depleted prior re-feeding. Greatly increased isotopic labeling highly purified with 14C-leucine during phase restoration levels result accelerated apoenzyme de novo.