牛磺酸对大鼠视网膜光化学损伤的防护作用

STUDY ON THE PROTECTIVE EFFECT OF TAURINE AGAINST PHOTOCHEMICAL DAMAGE IN RAT RETINA

目的:观察饲料中添加牛磺酸对持续高强度光照条件下大鼠视网膜的影响。方法:70只SD大鼠随机分为对照组,2%牛磺酸组(TauI),4%牛磺酸组(TauⅡ),饲料干预15d后光照(3000±200lx),持续24h,光照前后测定视网膜牛磺酸含量([Tau]r)和血清牛磺酸含量([Tau]s),并通过视网膜电图(scotopicelectroretinograph,Scot-ERG)、视网膜组织病理和超微结构变化判定牛磺酸的防护效应。结果:光照前TauⅡ组[Tau]s最高,光照后下降,TauⅡ组显著高于对照组和TauI组;光照前[Tau]r各组无显著差异,光照后TauⅡ组维持较高含量。Scot-ERG结果:光照后对照组波型不典型,a波、b波幅值显著降低,潜伏时间延长,TauI和TauⅡ组波型典型,其中TauⅡ组仅a波幅值下降;光照后对照组视网膜内外节段(retinaouter/innersegment,ROS/RIS)排列紊乱,外核层(outernuclearlayer,ONL)变薄,线粒体肿胀,而TauI和TauⅡ组视网膜结构保持良好,线粒体轻微肿胀。结论:喂饲牛磺酸尤其4%剂量对光化学损伤条件下视网膜有较强的保护作用。

Objective： To investigate the protective effect of taurine against photochemical damage in rat retina. Method： Seventy rats were randomly divided into control group, 2% and 4% taurine group （Tau Ⅰ ＆ Ⅱ ） . After 15 d dietary supplementation, all groups were exposed to 3 000±200 lx cool white light for 24 h. Levels of taurine in retina（[Tau]r） and serum （[Tau]s）were measured, and retina morphology and function were observed through light and electron microscopy and scotopic electroretinography （Scot- ERG） respectively. Results. Dietary supplementation with Tau increased [Tau]s, the highest in Tau Ⅱ group, however, little effect on [Tau]r. After light exposure, [Tau] s and [Tau] r were dramatically decreased in all groups, but in Tau Ⅱ group not significantly different with normal. After light exposure, a and b amplitude of Scot-ERGs decreased and a and b latent-time prolonged in control group, but the functional rescue was statistically significant in supplementation groups especially in Tau Ⅱ. No apparent morphological changes were observed in Tau II group after constant illumination, whereas disorderly retina inner/outer segments, thinner outer nuclear layer and swollen mitochondria were found in the control. Conclusion. Dietary supplementation with 4% taurine protects retina from photochemical damage after illumination. [ACTA NUTRIMENTA SINICA, 2006, 28（1）： 19-22]