Spector A
Ciba Found Symp. 1984;106:48-64. doi: 10.1002/9780470720875.ch4.
Previous work has established that oxidation of the constituents of the human lens is an early event in the development of cataract. In old pre-cataractous lenses, oxidation of the fibre membrane polypeptides is observed. Non-disulphide-linked aggregates possibly generated by photo-oxidation are also found. With the development of cataract the oxidation becomes more extensive, affecting many of the proteins of the tissue. High molecular weight, disulphide-linked aggregates are formed, involving cytosol and membrane components. Membrane rupture accompanies the process. Hydrogen peroxide has been found in elevated levels in the aqueous fluid of some cataract patients. H2O2 will cause cataract and has been shown to affect Na+,K+-ATPase. Analyses of available data suggest that (1) oxidation of membrane components may be an initiating event in cataract, and (2) the oxidizing agent may come from the exterior environment of the tissue. The problems involved in proving this hypothesis are discussed and an approach to testing the hypothesis is suggested.
以往的研究已经证实，人晶状体成分的氧化是白内障形成过程中的早期事件。在老年前期白内障晶状体中，可观察到纤维膜多肽的氧化。还发现了可能由光氧化产生的非二硫键连接的聚集体。随着白内障的发展，氧化作用变得更加广泛，影响到组织中的许多蛋白质。形成了高分子量的、二硫键连接的聚集体，涉及胞质溶胶和膜成分。该过程伴随着膜破裂。在一些白内障患者的房水中发现过氧化氢水平升高。过氧化氢会导致白内障，并且已被证明会影响钠钾ATP酶。对现有数据的分析表明：（1）膜成分的氧化可能是白内障的起始事件；（2）氧化剂可能来自组织的外部环境。文中讨论了证明这一假设所涉及的问题，并提出了一种检验该假设的方法。
