人類不同年齡晶體巰基含量的變化和年齡相關性白内障形成的關系

目的使用傳統的巰基顯色劑Ellman試劑測量并比較分析人類不同年齡段的透明及各類型白内障晶狀體樣本中非蛋白巰基(游離巰基)、蛋白巰基和蛋白結合巰基的含量,并分析其與人類年齡相關性白内障形成的關系.方法44個人類晶體按年齡大小被分爲5組,其中10個白内障晶體被分成2組(皮質性和核性).用Ellman試劑測量以上樣品的晶體非蛋白巰基、總蛋白巰基和總蛋白結合巰基含量.結果 皮質性白内障晶狀體的非蛋白巰基含量顯著高于核性白内障晶狀體(P＜0.01);而在蛋白巰基和蛋白結合巰基中,兩者則無顯著差别(P＞0.05).非蛋白巰基含量從胚胎期到年齡相關性白内障發生逐漸降低,各年齡組均顯著小于前一年齡組(P＜0.01);蛋白巰基含量在第5組顯著高于第1、2、3、4組(P＜0.05),其余各組間無顯著區别(P＞0.05);蛋白結合巰基含量除第3、4組和第4、5組間無顯著區别外(P＞0.05),其余組均顯著低于較小年齡組(P＜0.01).結論 人類年齡相關性白内障的形成過程中,晶狀體蛋白分子間巰基的氧化并不像在其它實驗性白内障模型中那樣起决定作用.

Changes of human lens sulphydryl contents in different ages and their relation with age- related cataract

To determine and compare the contents of nonprotein sulphydryl(SH), protein SH and protein - bound SH in human normal and age related cataractous lens at different ages by traditional Ellman reagent and to study their roles in age - related cataract. Methods 44 human lenses samples were collected and divided into 5 groups according to age, and the 10 cataract lenses of the samples were divided into 2 groups (cortical and nuclear). Ellman reagent was used to determine the contents of nonprotein SH, total protein SH and total protein -bound SH in the above lens. Results The content of nonprotein SH in cortical cataract lenses was significantly higher than that in nuclear cataract lenses(P<0.01). But no significant difference was observed in the content of protein SH and protein - bound SH between the two kinds of cataract lenses(P> 0.05). The content of nonprotein SH in lenses decreased with age. The content of protein SH in Group 5 was significantly higher than that in other groups(P< 0.05) , and no significant difference was found among group 1,2,3 and 4(P> 0.05) . The content of protein - bound SH was not significantly different between group 3 and 4, Group 4 and 5, but the younger groups had higher values than the older one in other groups (P < 0.01). Conclusion Oxidation of SH inside human lens proteins in the mechanism of age - related cataractogenesis is not as important as that in other experimental cataract model.