视神经挫伤对大鼠视网膜谷氨酰胺合酶和兴奋性氨基酸转运蛋白-2表达的影响

目的通过谷氨酰胺合酶(glutamine synthetase,GS)、兴奋性氨基酸转运蛋白-2(GLT-1)表达的改变,研究视神经挫伤后视网膜谷氨酸代谢变化的机制。方法建立大鼠右眼视神经挫伤模型48只。术后1d、7d、14d以高效液相色谱分析检测大鼠玻璃体谷氨酸浓度;通过免疫组织化学检测大鼠视网膜GS、GLT-1的表达。结果视神经挫伤后1d、7d、14d,大鼠玻璃体谷氨酸浓度升高,与对侧眼比较差异具有统计学意义(P=0.0011、P=0.0000、P=0.0000)。视神经挫伤后1d,GS高表达(P=0.0054);挫伤后7d,GS表达与对侧眼比较差异无统计学意义(P=0.1379);挫伤后14d,GS低表达(P=0.0333)。视神经挫伤后1d、7d,GLT-1的表达与对照组的差异无统计学意义(P=0.1985、0.6537);但挫伤后14d,GLT-1低表达(P=0.0403)。结论视神经挫伤后玻璃体谷氨酸浓度升高,与视网膜GS、GLT-1的表达降低有关。

Optical nerve contusion on expression of glutamine synthetase and G LT-1 in rat retina

Objective To investigate the expression of glutamine synthetase(GS)and GLT-1 in rat retina and mechanisms of retinal glutamic acid metabolism after optical nerve contusion.Methods Forty-eight Sprauge-Dawley(SD)rats were contused right optical nerve.Vitreous glutamate concentration was analyzed with high-performance liquid chromatography at 1 day,7 days,14 days post-contusion.The expression of GS and GLT-1 were measured by means of immunohistochemistry.Results The vitreous glutamate concentration of right eyes was higher than that of left eyes at 1 day,7 days,14 days post-contusion(P=0.001 1,P=0.000 0,P=0.000 0).GS expression of right eyes was increased at 1 day post-contusion(P=0.005 4),but was decreased at 14 days post-contusion(P=0.033 3),and with no significant difference comparing with left eye at 7 days post-contusion(P=0.137 9).GLT-1 expression of right eyes also decreased at 14 days post-contusion(P=0.040 3),and with no statistical difference comparing with left eye at 1 day and 7 days post-contusion(P=0.198 5,P=0.653 7).Conclusion Optical nerve contusion could decrease the expression of GS and GLT-1 in retina,which results in the increase of glutamate concentration.