地塞米松对兔视神经钳夹伤后视网膜神经节细胞存活及Nogo-A表达的影响

目的观察地塞米松对家兔视神经钳夹伤后视网膜神经节细胞(retinal ganglion cell,RGC)存活的影响及损伤视神经、视网膜Nogo-A表达的变化。方法采用兔球后视神经钳夹伤模型,健康成年家兔分为正常对照组、损伤组、治疗组。分别于损伤后3d、7d、14d处死动物,观察单位面积RGC存活数量及损伤后Nogo-A在视神经、视网膜的表达变化。结果视神经损伤后,治疗组RGC的存活数高于损伤组及对照组(P<0.01)。对照组、损伤组损伤后3d、7d、14d视神经、视网膜Nogo-A表达增强,至损伤后7d达高峰;治疗组视神经、视网膜表达亦增强,各时间点均弱于损伤组、对照组,差异有显著统计学意义(P<0·01)。结论视神经损伤后,地塞米松能够增加RGC的存活数量,能够下调No-go-A的表达,这可能是地塞米松治疗作用机制之一。

Dexamethasone on retinal ganglion cells survival and Nogo-A expression after rabbit optic nerve trauma

Objective To observe the effect of dexamethasone on retinal ganglial cells(RGC) survival after optic nerve trauma and the changes in expression of Nogo-A in injured optic nerve and retina.Methods Intraorbital optic nerve trauma model of rabbit was used.Healthy adult rabbits were divided into control group,injured group,and treatment group.At 3 days,7 days and 14 days after injury,the rabbits were killed respectively.RGC survival and the expression of Nogo-A in optic nerve and retina were observed after injured.Results After optic nerve trauma,the numbers of survived RGC in treatment group were higher than those in control group and injured group(P<0.01).At 3 days,7 days and 14 days after injured,the expression of Nogo-A increased in optic nerve and retina in control group and injured group,and reached to the peak at 7 days after injured.The expression of Nogo-A also increased in optic nerve and retina in treatment group,but was less than that in control group and injured group(P<0.01).Conclusion After optic nerve injured,dexamethasone can increase the number of survived RGC and can down regulate the expression of Nogo-A,which maybe one of its possible therapeutic effects.