【作者】 李双；

【导师】 姜发纲；

【作者基本信息】 华中科技大学 ， 眼科， 2007， 硕士

【摘要】 [目的]研究蛋白激酶C(PKC)特异性抑制剂—金丝桃素(hypericin)对兔慢性高眼压视网膜谷氨酸含量的影响。[方法]取32只成年家兔,后房内注射a-糜蛋白酶,建立兔慢性高眼压模型,以眼压>30mmHg为造模成功。造模成功10 d后12只兔眼玻璃体内注入0.1 ml金丝桃素,另12只注入等量生理盐水,剩余3只作为阴性对照。另用3只正常兔做空白对照。用高效液相色谱法测定玻璃体注射后1d,4d,7d,14d的视网膜谷氨酸含量。[结果]正常兔眼眼压平均为(19.32±1.45)mmHg,慢性高眼压的实验模型平均眼压为(34 .12±2.31) mmHg。正常兔视网膜谷氨酸含量为(1.71×10-5±0.23×10-5) mmol/g,慢性高眼压兔视网膜谷氨酸含量为(4.65×10-5±0.12×10-5)mmol/g,后者比前者显著升高(t=6.318,P=0.021)。金丝桃素处理组视网膜谷氨酸含量与同期生理盐水处理组相比,二者差异有统计学意义(t=7.156, P=0.019, t=7.933, P=0.016, t=11.993, P=0.007, t=5.276, P=0.034)。[结论]慢性高眼压兔视网膜谷氨酸含量显著升高,金丝桃素玻璃体腔注射能显著抑制视网膜谷氨酸含量的升高。[目的]探索金丝桃素对兔慢性高眼压视网膜神经节细胞的影响。[方法]取28只成年家兔,后房内注射a-糜蛋白酶,建立兔慢性高眼压模型。造模成功后取8只兔作为阴性对照,其余的兔眼在眼压稳定升高10d后玻璃体内分别注入金丝桃素0.1ml或生理盐水0.1ml,每wk 1次,连续2wk。另用4只正常兔做空白对照。最后应用光学显微镜和透射电镜分别观察视网膜神经节细胞的组织结构变化并测量视网膜内层平均厚度。[结果]生理盐水对照组和阴性对照组视网膜神经节细胞数量明显减少,部分细胞严重变性,染色质边集,线粒体、内质网等细胞器严重肿胀,视网膜内层平均厚度明显变薄。金丝桃素处理组神经节细胞形态结构较生理盐水对照组损伤轻微,节细胞数量稍有减少,部分细胞变性,染色质边集,线粒体、内质网肿胀较轻。测得空白对照组正常兔视网膜内层平均厚度为(78.62±1.87)μm,阴性对照组视网膜内层平均厚度为(59.30±2.17)μm,金丝桃素处理组视网膜内层平均厚度为(73.80±5.61)μm,生理盐水对照组视网膜内层平均厚度为(58.75±3.12)μm。前两者相比较,统计学上有显著性差异(t=3.254,P=0.005),后两者相比较,统计学上也有显著性差异(t=3.189,P=0.003)。[结论]金丝桃素作为一种特异性的蛋白激酶C抑制剂,对慢性高眼压下兔视网膜神经节细胞有保护作用。更多还原

【Abstract】 [Objective] Research has proved that the apoptosis of retinal ganglion cells is closely linked to the retinal excitotoxicity induced by glutamate, and glutamate plays an important role in the pathogenesis and progress of glaucoma. The present study was to explore the effect of hypericin, a specific protein kinase C antagonist, on retinal glutamate levels in chronic ocular hypertension rabbits.[Methods] Thirty-two rabbits were used to establish chronic ocular hypertension model by posterior chamber injection of alpha-chymotrypsin to elevate the intraocular pressure(IOP) to 30mmHg or more. Ten days after modeled, 0.1ml hypericin or saline was injected into the vitreous cavity of 24 successful models. Three rabbits from the each group were sacrificed for retinal glutamate detect by High Performance Liquid Chromatography (HPLC) at 1 day, 4 days, 7 days and 14 days after the injection. Three more successful models without intravitreous injection and 3 normal rabbits without any treatment were served as controls.[Results] The mean IOP was (19.32±1.45)mmHg in normal rabbit eyes and (34.12±2.31) mmHg in experimental rabbit eyes. The mean retinal glutamate level was (1.71×10-5±0.23×10-5) mmol/g in the normal rabbit eyes and(4.65×10-5±0.12×10-5)mmol/g in chronic ocular hypertension group.The latter increased significantly in comparison with the former(t=6.318,P=0.021). Retinal glutamate levels was significantly decreased in the hypericin-treated eyes in comparison with saline-treated eyes at various time points(t=7.156, P=0.019, t=7.933, P=0.016, t=11.993, P=0.007, t=5.276, P=0.034).[Conclusion] Chronic ocular hypertension can induce the increase of retinal glutamate level. Intravitreal injection of hypericin can inhibit the increase of the retinal glutamate level. [Objective] To explore the effect of hypericin on retinal ganglion cell in chronic ocular hypertension rabbits.[Methods] Twenty–eight rabbits were used to establish chronic ocular hypertension model by posterior chamber injection of alpha-chymotrypsin to elevate the intraocular pressure(IOP) to 30mmHg or more. Ten days after modeled, 0.1ml hypericin or saline was injected into the vitreous cavity of 16 successful models once a week for two weeks. Other eight successful models and four normal rabbits were as controls .All rabbits from each group were sacrificed and eight eyeballs were extracted. Retinal ganglion cells of these rabbit eyes were observed by light microscopy and electron microscopy .Also the mean thinckness of inner retina layer(MTIRL) were examined .[Results] The number of retinal ganglion cells in saline control group and control group decreased significantly.There was serious cell degradation with perinuclear condensation of chromatin and swelling organelles. But the change was slight in hypericin-treatedt group.The normal MTIRL was(78.62±1.87)μm.The difference of MTIRL between the normal group and the control group was significant(t=3.254,P=0.005). Also the MTIRL was significantly decreased in the saline-treated eyes in comparison with hypericin-treated eyes(t=3.189,P=0.003).[Conclusion] Intravitreal injection of hypericin as a protein kinase C antagonist can protect the retinal ganglion cell in chronic ocular hypertension rabbits .更多还原