中文摘要：

目的：观察依托咪酯（ET）对成年大鼠视神经切断后视网膜神经节细胞（RGC）存活的作用。 方法：成年雌性SD大鼠42只,眶内距视神经根部1mm处切断左侧视神经,残端留置浸有荧光金（50g/L）的明胶海绵逆行标记RGC。术后大鼠随机分为ET（4mg/kg,ip,1次/d）治疗组、1,2-丙二醇（PG）溶剂对照组、生理盐水对照组和正常对照组。再根据术后不同存活时间将前3组动物分为7d和14d两个亚组,正常对照组动物则存活2d。于相应存活时间点处死动物,取出各组大鼠左侧视网膜平铺后计数存活RGC并得出RGC的平均密度。 结果：术后7dET治疗组存活RGC平均密度为1307±55/mm^2,显著高于PG对照组（1128±75/mm^2）和生理盐水对照组（1068±75/mm^2,P〈0.001）。然而,未能在术后14d观察到ET的这种保护作用,因为ET治疗组存活RGC平均密度（210±36/mm^2）与PG对照组（215±20/mm^2）和生理盐水对照（208±19/mm^2）间无显著差异（P〉0.05）。 结论：ET在视神经切断后一定时期内对RGC具有神经保护作用。

英文摘要：

AIM： To investigate the effects of etomidate on the survival of retinal ganglion cell （RGC） following intraorbital optic nerve （ON） transection in adult rats. METHODS： The left ONs of 42 adult female SD rats were transected at 1mm from the optic disc. The animals were divided into the etomidate-treated （4mg/kg, ip, once a day）, propylene glycol （PG）-treated, saline-treated and normal control groups. Animals in the first three groups were allowed to survive for 7 or 14 days, and those in the normal control group for 2 days. After the animals were killed, retrogradely labeled surviving RGCs were counted in the fiat-mounted retinas and the mean RGC density was estimated. RESULTS： Etomidate significantly promoted the mean density of surviving RGC （1 307±55/mm^2, P〈0.001） 7 days after ON transection, when compared with those in PG- （1 128±75/mm^2） and saline- （1 068±75/mm^2） treated control animals. This neu roprotective effect of etomidate, however, was not detected at 14 day because the mean density （210±36/mm^2） in etomidate-treated group was similar to those in the PG- （215±20/mm^2） and saline-treated （208±19/mm^2） animals （P〉0.05）. CONCLUSION： Etomidate has a marked neuroprotective effect on the axotomized RGC at certain period after ON transection.