美金胺对急性高眼压大鼠视网膜神经节细胞保护作用的实验研究

目的探讨美金胺对急性高眼压大鼠视网膜神经节细胞（retinal ganglion cells，RGCs）的保护作用。方法以生理盐水在前房内加压灌注制作大鼠急性高眼压模型，然后腹腔内注射美金胺或生理盐水，分为美金胺治疗组和急性高眼压对照组各20只，另设健康对照组大鼠8只。采用免疫组织化学法和脱氧核苷酸末端转移酶介导的脱氧尿苷三磷酸末端标记法（terminal deoxynucleotidyl transferase mediated 2＇-deoxyuridine 5＇-triphosphate-biotin nick end labeling，TUNEL），检测大鼠RGCs caspase-3和凋亡细胞的表达。结果健康对照组无caspase-3与凋亡细胞表达。急性高眼压对照组在高眼压6h后视网膜出现凋亡细胞，逐渐增加至24h达高峰，后逐渐减少，72h时仅有少数凋亡细胞；caspase-3表达改变与凋亡细胞表达相似。美金胺治疗组的变化规律同急性高眼压对照组。急性高眼压6，24和72h后凋亡细胞与caspase-3的表达在3组间的差异均有统计学意义（P值均〈0．01）。结论细胞凋亡可能在视网膜急性高眼压损伤过程中起重要作用，美金胺对RGCs具有保护作用。

Neuroprotective effect of memantine on retinal ganglion cells in rats with acute ocular hypertension: an experimental study

Objective To determine the protective effect of memantine on the retinal ganglion cells（RGCs） of the rats with acute ocular hypertension. Methods Acute ocular hypertension models were made by perfusing normal salineinto anterior chamber. Then the model rats were treated by intraperitoneal injection of memantine（ memantine treated group,20 rats） or normal saline（ acute ocular hypertension group,20 rats）. Other 8 rats were set as control. The expression of caspase-3 and apoptosis in the RGCs of the rats were determined by immunohistochemistry and terminal deoxy-nucleotidyl transferase mediated 2＇-deoxy uridine 5＇-triphosphate-biotin nick end-labeling（TUNEL） method respectively. Results No caspase-3 expression or apoptosis was seen in the control group. In acute ocular hypertension group,apep- tosis began to appear in the retina 6 hours after ocular hypertension and increased gradually with the peak appeared at 24 hours, then decreased progressively. Only a few apeptotic cells could be found at 72 h. Changes in caspase-3 expression followed a similar trend. Changes in the memantine treatment group were similar to the ocular hypertension control group. There was significant difference among 3 groups in the caspase-3 positive cells and apoptosis cells （ P 〈 0.01 ）. Conclusions Apoptosis might play a vital role in the injury of retina after acute ocular hypertension and memantine could protect RGCs from damage.