白内障形成过程中晶状体细胞膜上脂类与蛋白质氧化的时间差异性

用马来酰亚胺及５恶唑氮氧自由基硬脂酸分别标记晶状体细胞膜中蛋白质及脂类，以电子自旋共振方法研究在三硝基甲苯、亚硒酸钠、半乳糖、平阳霉素及紫外线等白内障诱发剂作用下，晶状体细胞膜的氧化损伤变化。结果发现当晶状体细胞暴露于空气中时，晶状体细胞膜脂类氧化早于蛋白质的氧化；在五种白内障诱发剂作用下，均是如此．这说明白内障的形成首先是由膜中脂类氧化所引起。

Lipid Oxidized Prior to Protein in the Lens Cell Membrane during Cataractogenesis

Two spin labels, 5-doxyl stearic acid and maleimide were used to investigate oxidative damage which occured in cell membranes of rat lens after adding cataractogenic agents such as trinitrotoluene, sodium selenite, galactose, pingyangmycin and ultraviolet irradiation , In labelling the lens cells, we find 25 minutes to be the proper lablling time. In order to ascertain reliability of the system, the labelled lens cells were first exposed to air. The results showed that membrane lipids of lens cells were oxidized earlier than membrane proteins when the cells were exposed to air at 37 ℃ for 25 min; likewise the lipids were also oxidized prior to the proteins by the actions of the above mentioned cataractogenic agents at 37 ℃. This demonstrates definitly that the formation of cataract begins with lipid oxidaton in the lens cell membranes.