Richter V, Rotzsch W
Z Alternsforsch. 1977;32(6):555-9.
The intracellular enzyme level is a function of both the rate of synthesis and the rate of degradation. During aging the levels of a number of enzymes in various animal organs have been found to change; some increase, others decrease. These age dependent changes in enzyme levels may be the result of an alteration in either the rate of enzyme synthesis, or of enzyme degradation or both. The degradation rate constants and the half-life times of citrate cleavage enzyme and glucose-6-phosphate dehydrogenase are uneffected by age, whereas the enzyme levels decrease. Thus the decreased enzyme levels in the liver of old rats can be ascribed to a diminished rate of enzyme synthesis. The half-life time of malic enzyme decreases in dependence of age and the increased enzyme degradation contributes to the diminished enzyme level in the liver old rats.
细胞内酶水平是合成速率和降解速率的函数。在衰老过程中，已发现各种动物器官中多种酶的水平会发生变化；有些增加，有些减少。这些与年龄相关的酶水平变化可能是酶合成速率、酶降解速率或两者改变的结果。柠檬酸裂解酶和葡萄糖-6-磷酸脱氢酶的降解速率常数和半衰期不受年龄影响，而酶水平却下降。因此，老年大鼠肝脏中酶水平的降低可归因于酶合成速率的降低。苹果酸酶的半衰期随年龄增长而缩短，酶降解增加导致老年大鼠肝脏中酶水平降低。
