目的:研究αB-晶体蛋白对大鼠急性高眼压后视网膜组织中αB-晶体蛋白含量,视网膜神经节细胞(retinal ganglion cells,RGCs)中生长相关蛋白-43(growth associated protein-43,GAP-43)表达和全视野视网膜电流图(full-field ERG,F-ERG)的b波振幅差异,探讨αB-晶体蛋白对急性高眼压后RGCs轴突再生的影响.方法:采用随机分组设计的实验研究.本实验选择120只健康、无眼疾SD大鼠,随机分为以下4组:αB晶体蛋白组(αB)30只,生理盐水组(S)30只,假手术组(P)30只,急性高眼压组(H)30只,均以右眼为实验眼,分别于术后7d和14d各取5只术眼的视网膜,行Western-blot法,观察急性高眼压后视网膜中αB-晶体蛋白的表达;术后7,14,21d各取5只术眼的视网膜,行免疫组织化学法,观察急性高眼压后RGCs的GAP-43表达;术前和术后1mo时应用全视野ERG的b波振幅变化测定视网膜功能.组间数据比较采用单因素方差分析(One-way ANOVA),组间两两比较采用SNK-q检验.结果:αB组视网膜中αB-晶体蛋白的表达于术后7d较高,14d时表达减弱(P =0.000),但同一时间点明显高于其他三组(P=0.006,P=0.024,P=0.007;P=0.006,P=0.008,P=0.010);αB组RGCs的GAP-43表达于术后7d达高峰,14d时表达减弱,21d时仍有少量表达(P=0.000),但各时间点明显高于其他三组(P=0.001,P=0.002,P=0.001;P=0.015,P=0.002,P=0.006;P=0.005,P=0.003,P=0.005);ERG- b波振幅于术后1mo较低(P=0.014,P=0.004,P=0.003,P=0.006),其中术前各组ERG-b波振幅无明显差异(P=0.993),术后1mo时αB组ERG-b波振幅明显高于其他三组(P=0.000,P=0.004,P=0.002).结论:外源性αB-晶体蛋白能够提高视网膜αB-晶体蛋白的表达; αB-晶体蛋白通过促进RGCs中GAP-43的表达,从而促进RGCs的轴突再生;αB-晶体蛋白可促进视网膜功能的恢复,对大鼠视网膜无毒性作用.%AIM: To study the effects of αB-crystallin on the αB-crystallin content in retina, growth associated protein-43 (GAP-43) expression of retinal ganglion cells (RGCs), amplitude of electroretinogram (ERG) b-wave, and to investigate the promotive effect of αB - crystallin on axonal regeneration of RGCs after acute ocular hypertension( AOH).METHODS: One hundred and twenty male Sprague-Dawley (SD) rats (220±10g) were randomly divided into four groups (thirty in each group). αB group, (AOH following intravitreal injection of αB crystallin group, n = 30). S group, (AOH following intravitreal injection of normal saline solution group, n = 30). P group, (AOH following vitreous puncture group, n = 30). H group, (AOH group, n = 30). Western blot was assayed aB-crystallin content 7 and 14 days after model; Immunohistochemistry was observed GAP-43 expression 7, 14 and 21 days after model established; Amplitude of ERG b-wave was tested retinal function before and 1 month after model.RESULTS: The αB content in retina of αB group was higher 7 days after model established, fewer 14 days after model (P= 0.000, P=0.000, P= 0. 001, P=0.000). But the αB content in retina of αB group was more serious compared with other groups at the same time points (P=0. 019, P= 0.016); The GAP-43 expression of RGCs in αB group was highest 7 days after model established, started to decrease 14 days after model established, which was fewest 21 days after model established (P= 0.000, P= 0.000, P= 0.000, P= 0.000). But the GAP-43 expression of RGCs in αB group was significantly higher than in other groups at each time point (P =0.002, P =0.011, P =0.009); The amplitude of ERG b-wave was lower 1 month after model (P= 0.014, P= 0.004, P= 0.003, P= 0.006). There were no statistical differences among groups on amplitude of ERG b-wave before model established (P=0. 993). The amplitude of ERG b-wave in αB group was higher than others 1 month after model (P= 0.002).CONCLUSION: Exogenous αB-crystallin could improve αB - crystallin expression of retinas; αB - crystallin contributed to the increase of GAP - 43 expression of RGCs and RGCs axonal regeneration; αB-crystallin could promote the recovery of retinal function and was non-toxic on retinas of rat.
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