银杏叶提取物对谷氨酸诱导的兔视网膜NO水平及细胞凋亡的影响

目的 :探讨银杏叶提取物 (extract of ginkgo biloba ,EGB)对谷氨酸诱导的兔视网膜NO水平及细胞凋亡的影响作用。方法 :利用谷氨酸兔玻璃体内注射 ,诱导视网膜细胞凋亡的模型 ,眼球后注射不同剂量的EGB ,采用分光光度法测定兔视网膜NO水平 ,琼脂糖凝胶电泳分析视网膜细胞DNA断裂。结果 :实验对照组视网膜的NO的水平与空白对照组相比显著增加 (P<0.001) ,EGB大剂量治疗组视网膜NO水平比实验对照组显著降低 (P<0.001) ,EGB小剂量治疗组视网膜的NO水平与实验组相比轻度降低 ,但无统计学差别。EGB大剂量治疗组和空白对照组视网膜细胞无DNA凋亡样断裂 ,而实验组和EGB小剂量治疗组视网膜细胞DNA凋亡样断裂。结论 :银杏叶提取物可能通过抑制谷氨酸诱导的兔视网膜NO自由基的产生而抑制细胞凋亡 ,对谷氨酸诱导的兔视网膜损伤具有重要保护作用。

Effects of Extracts of Ginkgo Biloba (EGB) on Levels of Nitric Oxide and Apoptosis in the Retina Induced by Glutamate in Adult Rabbits

Objective: To study the effects of extracts of ginkgo biloba (EGB) on the levels of nitric oxide(NO) and apoptosis in the retina induced by glutamate by intravitreal injection in adult rabbit . Method: The model of apoptosis in retina induced by glutamate by intravitreal injection was established in adult rabbit and EGB was retrobulbarly injected.The levels of NO were measured by spectrophotometer. Retina DNA fragmentation was determined by agarose gel eletrophoresis. Result: The levels of NO in retina in experiment groups were significantly increased compared with controls, after treatment with high dosage of EGB, and levels of NO was decreased to normal. They were not decreased by injection of small dosage of EGB.DNA fragmentation of retina apoptosis was detected in experiment groups and small dosage EGB groups. Conclusion The retina apoptosis was induced by glutamate by intravitreal injection in adult rabbit and was inhibited by EGB that may be through blocking the generation of NO free radicals.