地西泮对大鼠视神经切断后视网膜神经节细胞保护作用的研究  

Protective effects of diazepam on retinal ganglion cells after optic nerve transection in rats

作　　者：刘玲[1] 武明媚[1] 游思维[1] 

机构地区：[1]第四军医大学全军神经科学研究,所陕西省西安市710032

出　　处：《眼科新进展》2009年第11期805-807,814,共4页Recent Advances in Ophthalmology

基　　金：国家自然科学基金资助(编号:30872829,30571998);陕西省攻关计划课题资助[编号:2007K15-01(2)]~~

摘　　要：目的探讨地西泮对成年大鼠视神经切断后视网膜神经节细胞(retinal ganglion cells,RGC)的保护作用及机制。方法取雌性SD大鼠36只,随机平均分为2组,麻醉后于眶内距视神经根部1.5 mm处切断左侧视神经,眶侧残端留置浸有荧光金的明胶海绵以逆行标记RGC。术前30 min及术后每天腹腔注射地西泮(地西泮组)和生理盐水(对照组),分别于术后2 d、7 d及14 d各处死6只大鼠。根据上述实验结果,将另外24只大鼠平均随机分为2组,每天腹腔注射γ-氨基丁酸A型(GABAA)受体阻断剂荷苞牡丹碱(荷苞牡丹碱组)和荷苞牡丹碱+地西泮(联合应用组)以探讨地西泮的神经保护机制,2组在动物存活2 d及7 d后分别处死6只大鼠。动物处死后视网膜平铺,计数每只动物荧光金标记的存活RGC并得出存活RGC的平均密度。比较各组RGC密度。结果地西泮组视神经切断后7 d RGC平均密度(1 730±75)mm-2显著高于同一时间点对照组RGC密度(1 095±94)mm-2。在此时间点,联合应用组RGC密度(1 120±63)mm-2明显低于地西泮组,而荷苞牡丹碱组与对照组RGC密度差异无统计学意义(P>0.05),说明地西泮对RGC的保护作用可被荷苞牡丹碱拮抗。结论地西泮可通过激活GABAA受体的途径在大鼠视神经切断后7 d促进RGC的存活。Objective To investigate the protective effects and mechanisms of diazepam on survival of retinal ganglion cells（RGC） after optic nerve transection in adult rats.Methods Left optic nerves of 36 female Sprague-Dawley rats were transected at 1.5 mm to the root of optic nerves intraorbitally under anesthesia.Gelatin sponge with fluorogold remained at orbital stump to antidromically mark RGC.Diazepam（diazepam group;n=18） or normal sodium（control group,n=18） was intraperitoneally injected at 30 minutes before operation and after operation daily.Rats were sacrificed at 2 days,7 days and 14 days after operation,respectively,and there were 6 rats at each time point in each group.According to the forementioned experimental results,12 of other 24 rats were intraperitoneally injected GABAA receptor inhibitor bicuculline daily（bicuculline group） and the other 12 rats were intraperitoneally injected bicuculline and diazepam（combined application group） to investigate the neuroprotective mechanisms of diazepam.Rats were sacrificed at postnatal 2 days and 7 days,and 6 rats at each time point.Retina was titled after rats sacrificed to count survived RGC of each rat marked with fluorogold and get average density of survived RGC.RGC density was compared among groups.Results The mean density of survived RGC in diazepam group（1 730±75）mm-2 was significantly higher than that in control group（1 095±94）mm-2 at 7 days after optic nerve transection.At the same time point,RGC density in combined application group（1 120±63）mm-2 was significantly lower than that in diazepam group,but no significant difference was found in RGC density between bicuculline group and control group（P〉0.05）,which indicated that the protective effects of diazepam on RGC was inhibited by bicuculline.Conclusion Diazepam can promote the survival of RGC by stimulating GABAA receptor at 7 days after optic nerve transection in rats.

关 键 词：地西泮 荷苞牡丹碱 视神经切断 视网膜神经节细胞 大鼠 

分 类 号：R774.1[医药卫生—眼科]