微量元素硒、维生素E缺乏致大鼠眼晶体的生化和形态改变

本文研究了块硒、块维生素E大鼠眼晶体某些酶活性、自由基产生和过氧化物含量,以及晶体的形志学改变。结果表明,缺硒使大鼠晶体谷胱甘肽过氧化物酶(GSH-Px)活性显著下降,晶体GSH-Px活性与血液红细胞硒水平呈显著的正相关。各组晶体中均有g=2.0015的自由基存在,但缺硒组自由基含量显著高于对照组,晶体自由基含量与红细胞硒水平及晶体GSH-Px活性均呈显著的负相关,紫外线照射离体晶体诱发晶体产生g=2.0097的自由基,缺硒组自由基的增加量也显著地高于对照组。维生素E缺乏使晶体超氧化物歧化酶(SOD)和谷胱甘肽还原酶(GSSG-R)活性显著下降,并使缺硒大鼠晶体GSH-Px活性进一步下降。硒或/和维生素E缺乏均导致晶体丙二醛含量显著增高,并出现早期的形志学改变。因此,硒或/和维生素E缺乏导致大鼠晶体抗氧化能力下降,自由基产生增加,脂质过氧化作用加强,并有早期的形态学改变,推测硒、维生素E缺乏与白内障的发生有密切关系。

BIOCHEMICAL AND MORPHOLOGICAL CHANGES IN THE LENS OF SELENIUM AND/OR VITAMIN E DEFICIENT RATS

The activities of glutathione peroxidase(GSH-Px), glutathione reductase (GSSG-R), superoxide dismutase(SOD) and the content of malondialdehyde (MDA) and free radicals were measured, and the morphological changes were observed in the lens of control rats, selenium-deficient (SeD) and/or Vitamin E deficient(VED) rats. The activities of GSH-Px in the lens of SeD rats decreased significantly. The GSH-Px activities of lens were positively related to RBC selenium level. There was a free radical at g = 2.0015 in the rat lens of all groups, but the content of free radicals in the lens of SeD group was signsficantly higher than that of the control group. The free radical content of lens was negatively related to RBC selenium level, as well as the GSH-Px activities in the lens. In vitro, ultraviolet radiation caused the generation of another free radical(g = 2.0097)in the lens of all groups, but the amount of the free radical in the lens of the SeD group was also significantly higher than that of the control group. The activities of SOD and GSSG-R in VED rat lens were significantly decreased. The amount of MDA of the lens in SeD and/or VED rats were significantly increased. The results showed tliat the decrease of antioxidative capability in the lenses of SeD and/or VED rats accelerated the lipid peroxidation and generation of free radicals. Although only early morphological changes in SeD and/or VED rat lens .were observed, it is considered that selenium and vitamin E deficiency may be involved in the occurence of cataract.