银杏叶提取物对急性缺血再灌注后视网膜神经节细胞的保护作用

The neuroprotective effect of extact of ginko biloba on retinal ganglion cells after retinal ischemia-reperfusion

目的探讨银杏叶提取物(EGb761)对大鼠急性高眼压诱导缺血再灌注模型中视网膜神经节细胞(RGCs)的保护作用。方法60只SD大鼠随机分为5组,右眼为损伤眼,行前房穿刺灌注形成110mmHg的眼压维持60min,左眼未损伤,作为空白对照。损伤后2h及此后每日1次灌胃给药,各组分别给予生理盐水5mg/kg、1%灯盏细辛5mg/kg、0.25%EGb7615mg/kg、1%EGb7615mg/kg和4%EGb7615mg/kg。动物损伤后第23天用荧光金行双上丘逆行标记,第28天取眼球标本做视网膜铺片并拍摄照片,计数RGCs并计算其的存活率。结果生理盐水组、1%灯盏细辛组、0.25%EGb761、1%EGb761和4%EGb761组RGCs存活率分别为66.58%、75.62%、74.92%、76.57%、79.87%。生理盐水组与各EGb761组之间差异均有统计学意义(q=0.00,q=0.19,q=0.10,P<0.01),不同质量浓度EGb761组之间差异均无统计学意义(q=0.22,q=0.13,q=0.45,P>0.05);1%灯盏细辛组与生理盐水对照组比较差异有统计学意义(q=0.16,P=0.02),与0.25%EGb761组、1%EGb761组、4%EGb761组比较差异均无统计学意义(q=0.20,q=0.01,q=0.50,P>0.05)。结论在急性高眼压诱导缺血再灌注模型中,银杏叶提取物能有效地保护RGCs。

Objective Loss of retinal ganglion cells （RGCs） is a dominant pathological feature after elevation of intraocular pressure（IOP）. Our previous study showed that ginkgo biloba extract has a neuroproteetive effect on RGCs. Present study was to investigate the effect of extact of ginko biloba on RGCs survival after acute ocular hypertention-induced retinal ischemia-reperfusion injury. Methods Retinal ischemia-reperfusion models were induced by infusing normal saline solution into anterior chamber to elevate IOP to 110mmHg for one hour and then reducing the IOP to normal reading to allow reperfusion in the right eyes of 60 SD rats. The normal fellow eyes were as controls. 5ml/kg of normal saline solution（NS）, 1% erigeron breviscapus （EB） ,0. 25% EGb761,1% EGb761,4% EGb761 was administered via lavaging at 2 hour after injury and once a day after operation for 28 days respectively in different groups. RGCs were retrogradely labeled by injection of 3% fluorogold into both side of superior colliculus at the 23th day after injury. The rats were sacrificed and retinas were collected at the 28th day after injury. Survival rate of RGCs was calculated at the ratio of RGCs density between right eyes and left eyes. Animal experiment followed the Standard of Association for Research in Vision and Ophthalmology. Results The mean survival rate of RGCs was 66.58%± 6.83%,75.62% ± 6.9%,74.92% ±6.78%,76.57% ±7.86%,79.87% ± 7.49% in NS group, 1% erigeron breviscapus group ,0.25% , 1% and 4% EGb761 group respectively, indicating significant difference among different groups（ F = 5.13,P = 0. 001 ）. Compared with NS group,the survival rate of RGCs was significantly elevated in 1% erigeron breviscapus （EB）group, 0.25% EGb761 group,1% EGb761 group and 4% EGb761 group（P 〈0. 05）. No significant difference was found among different doses of EGb761 groups（ P 〉 0.05 ） or between 1% EB group and different doses of EGb761 groups（ P 〉 0. 05 ）. Conclusion EGb761 has neuroproteetive effect on RGCs in acute IOP induced retinal ischemia-reperfusion injury.