THE ROLE OF ASCORBIC-ACID IN SENILE CATARACT
THE ROLE OF ASCORBIC-ACID IN SENILE CATARACT
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DOI：
10.1073/pnas.82.21.7193
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
LOHMANN, W
中科院分区：
文献类型：
--
作者：
BENSCH, KG;FLEMING, JE;LOHMANN, W
在晶体透镜中以高于葡萄糖浓度存在的还原酮抗坏血酸能够在透镜蛋白存在下经历非酶促“布朗宁”。我们研究了抗坏血酸在模型系统中使用牛血清白蛋白和透镜晶体蛋白的非酶布朗宁。当牛血清白蛋白，α-晶体蛋白或γ-晶体蛋白与[14 C]抗坏血酸孵育，黄色和棕色缩合产物的形成似乎与蛋白相关放射性的增加相关。这些产物的荧光光谱与人白内障晶状体匀浆的荧光光谱相似。我们认为透镜晶体蛋白与抗坏血酸的非酶促反应可能至少部分地导致老化透镜的颜色变化和导致老年性白内障的物理性晶状体退化。高饮食摄入的抗坏血酸并没有影响小鼠晶状体的荧光光谱，因此，我们假设的速度和程度的透镜状布朗宁反应必须取决于其他因素的眼睛的多组分抗氧化系统的恶化。
The reductone ascorbic acid, present in the crystalline lens in concentrations higher than those of glucose, is capable of undergoing nonenzymatic "browning" in the presence of lenticular proteins. We studied the nonenzymatic browning with ascorbate in model systems employing bovine serum albumin and lens crystallins. When bovine serum albumin, .alpha.-crystallin, or .gamma.-crystallin was incubated with [14C]ascrobic acid, the formation of yellow and then brown condensation products appeared to correlate with increasing protein-associated radioactivity. The fluorescence spectrum of these products was similar to that of homogenates of human cataractous lenses. We suggest that the nonenzymatic reaction of lens crystallins with ascorbic acid may contribute, at least in part, to the color changes of aging lenses and to the physical lenticular deterioration leading to senile cataract. High dietary intake of ascorbic acid did not affect the fluorescence spectrum of murine lenses; thus, we assume that the speed and extent of the lenticular browning reactions must depend on a deterioration of other factors of the multicompnent antioxidant system of the eye.