牛磺酸对大鼠视网膜超微结构损伤保护作用

Protective effects of taurine against retinal ultrastructural damage on rats

目的观察牛磺酸对N-甲基-D-天冬氨酸(N-methyl-D-aspartate,NMDA)兴奋毒性引起的大鼠视网膜组织结构及超微结构损伤的保护作用。方法在大鼠玻璃体腔内每眼注射5μl 4 mmol/L NMDA造成视网膜兴奋毒性损伤模型,20只成年雄性SD大鼠随机分为4组:正常对照组;NMDA组;NMDA+牛磺酸干预组(腹腔注射25 mg/kg牛磺酸);磷酸盐缓冲液(PBS)对照组。玻璃体注射后第4 d,测量视网膜总厚度及内层厚度并用透射电镜观察视网膜超微结构。结果NMDA使大鼠视网膜总厚度尤其是视网膜内层厚度变薄(P<0.001),超微结构显示内核层及节细胞层神经元发生变性改变,25 mg/kg牛磺酸干预可有效保护视网膜组织结构,削弱NMDA引起的视网膜超微结构损伤。结论牛磺酸在体内可有效保护NMDA引起的视网膜组织结构及超微结构损伤。

Objective To observe whether taurine has protective effects against N-methyl-D-aspartate （NMDA）-induced excitototxicity, especially in retinal histo pathological structure and ultrastructure in rat. Methods A rat model of retinal excitotoxicity injury induced by intravitreal injection of 5μl 4mmol/L NMDA in one eye. Twenty adult male Sprague-Dawley rats were divided into four groups： normal control, intravitreal injection of PBS control, NMDA group, NMDA injection and taurine treated group （intraperitoneal injection with 25mg/kg taurine）. At the 4th d of intravitreal injection, the retinal damage was evaluated by measurement of the thickness of whole retina and inner retinal layer, and observation of retinal ultrastructure. Resuits After injection of NMDA, the overall thickness of retina were reduced （P 〈 0.001 ）, especially in inner retinal layer （P 〈 0.001）compared to controls. Degenerative changes were observed in neural cells of inner nuclear layer and ganglion ceils layer by eledtron microscopy. These damages can be prevented by 25mg/kg taurine effectively. Conclusion Taurine treatment can effectively prevent the damage of NMDA-induced retinal histopathological structure and ultrastructure in rat.