Antioxidant enzymes of the human retina: Effect of age on enzyme activity of macula and periphery
Antioxidant enzymes of the human retina: Effect of age on enzyme activity of macula and periphery
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DOI：
10.3109/02713689609007621
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发表时间：
1996-03-01
影响因子：
2
通讯作者：
Fridovich, I
中科院分区：
文献类型：
--
作者：
DeLaPaz, MA;Zhang, J;Fridovich, I
本研究的目的是评估年龄对正常新鲜尸体视网膜黄斑和周边保护性抗氧化酶活性的影响。在从正常新鲜人类尸体视网膜的黄斑中心和上中周周围获得的 5 毫米视网膜环钻穿孔产生的组织提取物中测定了抗氧化酶。尸体组织取自各个年龄范围（7 至 85 岁）的捐献者。测定在摘除后 6 小时内和供体死亡后 24 小时内进行。测定的抗氧化酶包括超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和谷胱甘肽还原酶。对己糖激酶和葡萄糖-6-磷酸脱氢酶这两种不直接参与氧化损伤保护的酶进行了分析以进行比较。使用提取物的蛋白质浓度作为分母计算黄斑和外周的酶比活性。使用线性回归分析，在 25 至 75 岁的年龄范围内，外周而非黄斑的超氧化物歧化酶活性随着年龄的增长而下降（p = 0.04，R(2) = 0.21）。个体间的变异性很高，并且变异性随着年龄的增长而增加。随着供体年龄的增加，黄斑和外周谷胱甘肽过氧化物酶活性之间的差异趋于下降（p = 0.025，R(2) = 0.33）。年龄对过氧化氢酶、葡萄糖-6-磷酸脱氢酶和谷胱甘肽还原酶的比活性没有影响。黄斑中己糖激酶的比活性随着供体年龄的增加而下降(p = 0.022, R(2) = 0.43)。从死亡到摘除或开始实验的时间不是一个重要因素。 总之，年龄对正常人视网膜黄斑主要抗氧化酶的活性没有影响。年龄对外周超氧化物歧化酶活性以及黄斑和外周谷胱甘肽过氧化物酶活性之间的差异有影响。人类中抗氧化酶活性存在很大的个体差异。
The purpose of this research was to evaluate the effect of age on protective antioxidant enzyme activity of normal fresh cadaver human retina of the macula and periphery. Antioxidant enzymes were assayed in tissue extracts generated from 5 mm trephined punches of retina obtained centered over the macula and the superior midperiphery of normal fresh human cadaver retina. Cadaver tissue was obtained from donors of a wide age range (age 7 to 85 years). The assays were performed within 6 h of enucleation and within 24 h of donor death. Antioxidant enzymes assayed included superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Hexokinase and glucose-6-phosphate dehydrogenase, enzymes not directly involved in protection against oxidative damage, were assayed for comparison. Enzyme specific activities were calculated for the macula and periphery using protein concentration of the extract as the denominator. Using linear regression analysis, over the age range of 25 to 75 years, superoxide dismutase activity of the periphery but not the macula tended to decline with age (p = 0.04, R(2) = 0.21). Interindividual variability was high, and variability increased with age. The difference between the macular and peripheral enzyme activities for glutathione peroxidase tended to decline with increasing donor age (p = 0.025, R(2) = 0.33). There was no effect of age on the specific activities of catalase, glucose-6-phosphate dehydrogenase, and glutathione reductase. The specific activity of hexokinase from the macula declined with increasing donor age(p = 0.022, R(2) = 0.43). Time from death to enucleation or beginning of experiment was not a significant factor.In summary, age does not have an effect on the activity of major antioxidant enzymes of the macula in normal human retina. There is a tendency for an effect of age on peripheral superoxide dismutase activity and the difference between macular and peripheral glutathione peroxidase activity. High interindividual variability of antioxidant enzyme activity exists in humans.