Lin A T, Hsu T H, Yang C, Chang L S
Division of Urology, Department of Surgery, Veterans General Hospital-Taipei, Taiwan.
Urol Int. 2000;65(3):144-7. doi: 10.1159/000064860.
Our previous study showed that aged rat bladders became fatigued faster than young bladders following repeated contraction induced by electrostimulation. One factor might be a lower energy-producing capability secondary to a decreased mitochondrial enzyme activity of the aged bladder. This study examined this possibility.
Mitochondria from 3- (n = 11) and 24-month-old (n = 10) Sprague-Dawley rats were isolated. Activities of the following enzymes were assayed: two key enzymes in the citric acid cycle, citrate synthase and malate dehydrogenase, and three enzymes in the respiratory chain reaction, NADH-cytochrome c reductase, succinate-cytochrome c reductase and cytochrome c oxidase. The concentration of phosphocreatine and ATP in the aged rat bladders and a separate group of young bladders (n = 12) was determined using high-performance liquid chromatography.
(1) The aged bladders have a significantly lower level of phosphocreatine and ATP content than those of young bladders. (2) The activities of all five enzymes assayed were significantly lower in the aged bladders than in young bladders, especially for citrate synthase, which had only 46.8% of the activity of young bladders.
Aging reduces the mitochondrial enzyme activity of the rat bladder resulting in a lower energy-production capability, which might explain some of the voiding dysfunctions found in the elderly.
我们之前的研究表明，在电刺激诱导的反复收缩后，老年大鼠膀胱比年轻膀胱更快出现疲劳。一个因素可能是老年膀胱线粒体酶活性降低导致能量产生能力下降。本研究检验了这种可能性。
分离3月龄（n = 11）和24月龄（n = 10）的Sprague-Dawley大鼠的线粒体。检测以下酶的活性：柠檬酸循环中的两种关键酶，柠檬酸合酶和苹果酸脱氢酶，以及呼吸链反应中的三种酶，NADH-细胞色素c还原酶、琥珀酸-细胞色素c还原酶和细胞色素c氧化酶。使用高效液相色谱法测定老年大鼠膀胱和另一组年轻膀胱（n = 12）中的磷酸肌酸和ATP浓度。
（1）老年膀胱的磷酸肌酸水平和ATP含量显著低于年轻膀胱。（2）所检测的所有五种酶的活性在老年膀胱中均显著低于年轻膀胱，尤其是柠檬酸合酶，其活性仅为年轻膀胱的46.8%。
衰老降低了大鼠膀胱的线粒体酶活性，导致能量产生能力下降，这可能解释了老年人中发现的一些排尿功能障碍。
