Photoperoxidation in lens and cataract formation: preventive role of superoxide dismutase, catalase and vitamin C.
Photoperoxidation in lens and cataract formation: preventive role of superoxide dismutase, catalase and vitamin C.
复制标题
晶状体中的光过氧化和白内障形成：超氧化物歧化酶、过氧化氢酶和维生素 C 的预防作用。
DOI：
10.1159/000265189
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发表时间：
1982
影响因子：
2.1
通讯作者：
Richards,RD
中科院分区：
文献类型：
--
作者：
Varma,SD;Srivastava,VK;Richards,RD
在组织培养条件下，大鼠晶状体暴露在荧光日光(150英尺蜡烛)下，导致大量的脂质过氧化，丙二醛(MDA)的形成就是明证。在这样的光存在下孵育一夜的晶状体的丙二醛含量大约是在黑暗中培养的对照晶状体的6倍。这些培养物保存在类似房水的生理介质中，不含任何额外的光活性成分。因此，在其生理环境中，晶状体容易受到波长光自由穿透眼睛的光过氧化的影响。超氧化物歧化酶、过氧化氢酶和抗坏血酸可以抑制光过氧化，这表明所观察到的过氧化降解是通过光催化产生超氧化物并随后衍生成其他有效的氧化剂来启动的。这些研究首次提供了提示证据，表明老年性白内障的发展可能在一定程度上与体内房水和晶状体中来自周围氧气和光线的超氧化物和其他有效氧化剂的光化学生成有关；抗坏血酸由于其从血浆中的主动运输而在这种液体中保持在较高水平，在防止这些有效氧化剂的有害作用方面具有重要的生理意义。因此，这些研究首次表明，抗坏血酸对白内障和其他年龄、光线和氧气依赖的眼部异常具有迄今未被认识到的作用的可能性。此外，这项研究再次强调了组织过氧化氢酶和超氧化物歧化酶在预防组织光过氧化损伤中的作用。
Exposure of rat lens to fluorescent daylight (150 ft candles) under tissue culture conditions led to a substantial lipid peroxidation as evidenced by the formation of malonaldehyde (MDA). MDA content of lenses incubated overnight in presence of such light was approximately sixfold of that in the control lenses cultured in the dark. These cultures were maintained in physiological medium resembling aqueous humor which does not contain any additional photoactive component. Thus, the lens in its physiological surroundings is susceptible to photoperoxidation by light of wavelengths which freely penetrate the eye. Photoperoxidation could be thwarted by superoxide dismutase, catalase, and ascorbate, suggesting that the observed peroxidative degradation is initiated by photocatalytic generation of superoxide and its subsequent derivation to other potent oxidants. These studies provide for the first time suggestive evidence that senile cataract development may in part be linked to the in vivo photochemical generation of superoxide and other potent oxidants in the aqueous humor and lens derived from the ambient oxygen and light; and ascorbate which is maintained at high levels in this fluid by virtue of its active transport from plasma, is physiologically important in preventing the deleterious action of these potent oxidants. The studies thus indicate for the first time the possibilities of a hitherto unrecognized role of ascorbate against cataracts and other age-, light- and oxygen-dependent ocular abnormalities. In addition, the study re-emphasizes the role of tissue catalase and superoxide dismutase in the prevention of photoperoxidative damages to the tissue.