Spychała J, Marszałek J
Acta Biochim Pol. 1986;33(3):187-93.
Feeding high protein diet for 5 days caused a 3,5-fold and 2-fold increase of the activity of xanthine dehydrogenase (EC 1.2.1.37) and 5-nucleotidase (EC 3.1.3.31) respectively, in chicken liver. Six hours after feeding the high protein diet there was no change in either enzyme activity although a 3-fold increase in the level of serum uric acid was observed. High protein diet considerably decreased the activity of AMP deaminase at low, but not at high substrate concentration. The activity ratio, measured at 10.0 and 0.16 mM AMP increased from 14:1 (low protein diet) to 23:1 and 24:1 after 6 h and 5 days of high protein diet, respectively. It has been suggested that feeding birds a high protein diet may cause transformation of liver AMP deaminase (EC 3.5.4.6) from a low Km form toward a high Km form.
给鸡喂食高蛋白饲料5天，鸡肝脏中的黄嘌呤脱氢酶（EC 1.2.1.37）和5-核苷酸酶（EC 3.1.3.31）的活性分别增加了3.5倍和2倍。喂食高蛋白饲料6小时后，尽管观察到血清尿酸水平增加了3倍，但两种酶的活性均未发生变化。高蛋白饲料在低底物浓度时会显著降低AMP脱氨酶的活性，但在高底物浓度时则不会。在10.0 mM和0.16 mM AMP条件下测得的活性比，从（低蛋白饲料组的）14:1分别增加到高蛋白饲料喂养6小时后的23:1和喂养5天后的24:1。有人提出，给鸟类喂食高蛋白饲料可能会导致肝脏AMP脱氨酶（EC 3.5.4.6）从低Km形式转变为高Km形式。
