β-榄香烯对糖尿病大鼠视网膜中肿瘤坏死因子-α表达的影响

目的　探讨β-榄香烯对糖尿病大鼠视网膜肿瘤坏死因子-α（ｔｕｍｏｒｎｅｃｒｏｓｉｓｆａｃｔｏｒ-α,ＴＮＦ-α）表达的影响。方法　１０周龄ＳＤ大鼠３６只,随机分为６组,除Ａ组（每只大鼠腹腔注射等量的柠檬酸钠缓冲液）外其余组腹腔注射链脲佐菌素（ｓｔｒｅｐｔｏｚｏｔｏｃｉｎ,ＳＴＺ）制成糖尿病大鼠模型,成模６周后,Ｃ组每只大鼠双眼球周给予空白乳剂５μＬ,Ｄ组双眼球周给予β-榄香烯５μＬ,Ｅ组每只大鼠同时双眼球内给予空白乳剂５μＬ,Ｆ组双眼球内给予β-榄香烯５μＬ,Ｂ组未采取局部注射作为对照。末次给药４８ｈ后处死大鼠,取眼球固定视网膜行免疫组织化学法检测视网膜中ＴＮＦ-α的表达情况;提取视网膜蛋白,采用ＷｅｓｔｅｒｎＢｌｏｔ检测ＴＮＦ-α蛋白的表达情况。结果　免疫组织化学法检测结果显示:Ａ组视网膜未见阳性染色,Ｂ组视网膜全层可见阳性表达,Ｃ组及Ｅ组阳性表达分布与Ｂ组相同,而Ｄ组及Ｆ组棕色阳性表达下降,其中Ｆ组更显著。ＷｅｓｔｅｒｎＢｌｏｔ检测结果显示:Ｃ组及Ｅ组ＴＮＦ-α蛋白的表达与Ａ组相比差异均无统计学意义（均为Ｐ＞０．０５）,Ｂ组较Ａ组增高（Ｐ＜０．０１）,而Ｄ组及Ｆ组表达与Ｂ组差异均有统计学意义（均为Ｐ＜０．０５）。结论　β-榄香烯球周及球内注射均可降低糖尿病大鼠视网膜内ＴＮＦ-α的表达,且眼内注射效果更好。     

大鼠眼球标本石蜡切片的改良制作方法

目的探讨改良固定液固定大鼠眼球的效果。方法将大鼠眼球投入到由多聚甲醛、冰醋酸和丙酮组成的改良固定液中固定后制成石蜡切片，经HE染色后在显微镜下观察。结果眼球不变形，外观收缩不明显。镜下视网膜无脱落，眼球全层结构完整．视网膜各层细胞排列整齐，染色鲜艳。虹膜、睫状体、巩膜静脉窦和角膜等组织结构清楚。结论此改良方法明显优于其他方法，是适合大鼠眼球固定的一种有效方法。     

热休克蛋白A12B在大鼠角膜、晶状体和视网膜组织中的表达

目的　观察大鼠角膜、晶状体、视网膜中热休克蛋白Ａ１２Ｂ（ｈｅａｔｓｈｏｃｋｐｒｏｔｅｉｎＡ１２Ｂ,ＨＳＰＡ１２Ｂ）的表达。方法　取ＳＰＦ级ＳＤ大鼠９只,用水合氯醛处死后立即摘取眼球,采用Ｗｅｓｔｅｒｎｂｌｏｔ和ＲＴ-ＰＣＲ分别检测大鼠角膜、晶状体和视网膜组织中ＨＳＰＡ１２Ｂ蛋白和ｍＲＮＡ的表达情况;免疫荧光化学法观察ＨＳＰＡ１２Ｂ在角膜、晶状体和视网膜组织中的表达及定位。结果　Ｗｅｓｔｅｒｎｂｌｏｔ和ＲＴ-ＰＣＲ检测结果显示:ＨＳＰＡ１２Ｂ在大鼠角膜、晶状体、视网膜均有少量表达,其中角膜组织（０．２８０±０.０３４、０．３７４±０.０３１）中表达强度相对最低,晶状体（０．３３１±０．０３６、０．４５３±０．０４０）次之,视网膜组织（０．４５３±０．０２９、０．６８０±０．０４５）中表达强度最高。免疫荧光化学法结果表明,在角膜组织中ＨＳＰＡ１２Ｂ主要表达于上皮层,其中基底细胞染色最强,而角膜基质细胞上仅有弱表达;在晶状体组织中ＨＳＰＡ１２Ｂ主要表达于上皮细胞和皮质;在视网膜组织中ＨＳＰＡ１２Ｂ主要表达于视网膜神经纤维层、神经节细胞层和内核层,并与ＮｅｕＮ标记的神经元及ＧＳ标记的Ｍüｌｌｅｒ细胞存在共定位。结论　ＨＳＰＡ１２Ｂ在大鼠角膜、晶状体、视网膜组织中均有表达,且呈特异性表达。     

不同固定方法对豚鼠眼球后极部的固定效果比较

目的：为解决豚鼠眼球组织切片制备过程中所存在的视网膜脱片问题,采用不同固定方法,优化固定效果。

方法：2周龄正常豚鼠(75只)随机分为5个大组(A-E组),15个小组,每小组5只。A组(1-3小组)眼球分别置于FAS、Davidson固定液1(D1)和Davidson固定液2(D2)中固定24 h; B组(4-6小组)眼球在固定液中固定1 h后剪切角膜,再固定2 h; C组(7-9小组)眼球在固定液中固定1 h后沿视神经方向将眼球分为左右两半,再固定2 h; D组(10-12小组)眼球在固定液中固定3 h后将眼球分为左右两半; E组(13-15小组)眼球在固定液中固定3 h后剪切角膜。经苏木精-伊红(HE)染色比较各个小组眼球后极部固定效果。

结果：形态观察表明1-6小组、11-15小组眼球表面光滑圆润,色泽透明,7-10小组眼球凹陷皱缩变形。HE染色表明大部分组别眼球后极部组织切片卷曲缠绕,视网膜脱离; 1、5、6、14、15小组切片结构规整,其中14小组形态最佳,视网膜、脉络膜、巩膜连接紧密,组织结构清晰,细胞排列规整。

结论：采用D1固定液固定3 h后剪切角膜的固定效果最为理想,适用于豚鼠眼球后极部相关组织研究。     

小鼠视网膜组织石蜡切片制作方法的探讨

目的寻找一种效果好的视网膜固定方法.方法 30只小鼠取出眼球后在角巩膜缘刺一小口,A组24只眼球,用体积分数10%中性甲醛固定;B组16只眼球,用FAA固定液(体积分数10%中性甲醛10 mL、体积分数95%乙醇85 mL、冰醋酸5 mL混合)固定;C组20只眼球,置于FAA固定液中浸泡1 min后用体积分数10%中性甲醛固定过夜,脱水后去除角膜、虹膜和晶状体,分别做HE:染色和免疫组织化学染色,镜下观察其差异.结果大体观察A组大部分眼球皱缩变形,视网膜脱离率高;B组、C组眼球形态均无明显变化,无视网膜脱离发生.HE染色示A组标本视网膜结构疏松,有较多裂隙,且易发生视网膜碎裂;B组标本视网膜过度压缩,视网膜各层结构不清晰;C组标本视网膜结构清晰,细胞排列紧密,色泽艳丽.免疫组织化学染色3组均显示神经元特异性烯醇化酶NSE阳性,但C组标本染色效果优于A组、B组,且脱片程度低,适用于视网膜组织的固定.结论采用FAA先浸泡再用体积分数10%中性甲醛固定视网膜组织的效果优于单独使用体积分数10%中性甲醛和FAA固定液.     

玻璃体内注射色素上皮源性因子对大鼠早期糖尿病视网膜病变的保护作用

目的　观察玻璃体内注射色素上皮源性因子（ｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉｕｍ-ｄｅｒｉｖｅｄｆａｃｔｏｒ,ＰＥＤＦ）对ＳＤ糖尿病大鼠视网膜ＰＥＤＦ、血管内皮生长因子（ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ,ＶＥＧＦ）、炎性相关因子细胞间黏附分子-１（ｉｎｔｅｒｃｅｌｌｕｌａｒｃｅｌｌａｄｈｅｓｉｏｎｍｏｌｅ-ｃｕｌｅ-１,ＩＣＡＭ-１）和单核细胞趋化蛋白-１（ｍｏｎｏｃｙｔｅｃｈｅｍｏｔａｃｔｉｃｐｒｏｔｅｉｎ-１,ＭＣＰ-１）以及细胞通透性相关因子紧密连接蛋白-１（ｚｏｎｕ-ｌａｏｃｃｌｕｄｅｎｓ-１,ＺＯ-１）和蛋白激酶Ｂ（ｐｒｏｔｅｉｎｋｉｎａｓｅＢ,ＰＫＢ,又称Ａｋｔ）表达的影响,探讨ＰＥＤＦ对早期糖尿病视网膜病变的保护作用。方法　选取６～８周龄ＳＤ大鼠６０只,随机分为４组:正常对照组（ＣＯＮ组）、糖尿病组（ＤＭ组）、糖尿病生理盐水注射组（ＤＭ＋ＮＳ组）和糖尿病ＰＥＤＦ注射组（ＤＭ＋ＰＥＤＦ组）。链脲佐菌素诱导建立糖尿病模型后第１周、２周、３周时,ＤＭ＋ＰＥＤＦ组大鼠玻璃体内注射ＰＥＤＦ,而ＤＭ＋ＮＳ组注射同样体积的生理盐水。第４周时处死大鼠,摘出眼球,进行视网膜组织病理学及电镜观察。并采用免疫组织化学方法检测视网膜ＰＥＤＦ、ＶＥＧＦ、ＩＣＡＭ-１、ＭＣＰ-１以及ＺＯ-１、Ａｋｔ的表达情况。结果　糖尿病大鼠均造模成功。４周糖尿病病程尚不能导致明显的视网膜新生血管形成。在透射电镜下,ＤＭ组大鼠视网膜可见神经节细胞水肿,线粒体肿胀变大,基质肿胀明显,可见大部分或全部的嵴消失,部分双侧膜融合,粗面内质网扩张,而玻璃体内ＰＥＤＦ注射可以明显地改善这一病理改变。ＤＭ组大鼠ＰＥＤＦ主要表达于视网膜神经纤维层、神经节细胞层以及内丛状层、光感受器基质以及色素上皮层、脉络膜等部位;ＶＥＧＦ主要表达于神经节细胞层,ＩＣＡＭ-１主要表达在光感受器层,ＭＣＰ-１主要表达在视网膜内层细胞,包括节细胞层和内核层,ＺＯ-１蛋白主要表达于内核层的细胞以及神经节细胞,Ａｋｔ主要表达于内丛状层以及脉络膜的细胞浆中。同ＣＯＮ组相比,ＤＭ组、ＤＭ＋ＮＳ组视网膜中ＰＥＤＦ、ＶＥＧＦ表达差异均无统计学意义（均为Ｐ＞０．０５）,而ＩＣＡＭ-１、ＭＣＰ-１表达增加,ＺＯ-１、Ａｋｔ表达减少,差异均有统计学意义（均为Ｐ＜０．０５）。ＤＭ＋ＰＥＤＦ组大鼠视网膜中ＰＥＤＦ、ＶＥＧＦ的表达较ＤＭ组和ＤＭ＋ＮＳ组差异均无统计学意义（均为Ｐ＞０．０５）,但ＩＣＡＭ-１、ＭＣＰ-１表达减少,ＺＯ-１、Ａｋｔ表达增多,差异均有统计学意义（均为Ｐ＜０．０５）。结论　ＰＥＤＦ可以明显地改善糖尿病视网膜病变早期视网膜神经节细胞的损害,通过减少炎性因子和增加细胞连接蛋白而减轻血-视网膜屏障的破坏,从而对早期糖尿病视网膜病变起一定的防治作用。     

单疱病毒性角膜炎局部角膜免疫组化研究

目的 观察单纯疱疹病毒性角膜炎局部角膜免疫反应与其发 关系。方法 用ＨＥ染色及ＬＳＡＢ法染色对２１例ＨＳＫ病例角膜两全是及免疫组化观察。结果 组织病理显示ＨＳＫ活动期以多形核白细胞为主，少量单核样细胞。静止期以单核样细胞为主。免疫组化显示ＣＤ４、ＣＤ８、ＣＤ１４、ＣＤ１５、ＣＤ２０、ＣＤ６８、ＣＤ７１、ＨＬＡ－ＤＲ、ＨＳＶ－１、ＨＳＶ－２阳性率分别为１５．８％、１５．８％、４７．１％、２１．１％、     

增殖细胞核抗原及核仁组成区嗜银蛋白与视网膜母细胞瘤预后的…

探讨视网膜母细胞瘤细胞的增殖活性与患者预后的关系。应用抗增殖细胞核抗原单克隆抗体ＰＣ－１０，采用ＬＳＡＢ免疫组织化学方法及Ｐｌｏｔｏｎ银染技术，对４８例Ｒｂ石蜡标本进行ＰＣＮＡ和核仁组成区嗜银蛋白检测。结果 Ｒｂ组织ＰＣＮＡ标记与其相对应组织切片的ＡｇＮＯＲｓ计数有显著相关性。     

三种不同固定液对豚鼠眼球的固定效果比较

目的：用过碘酸雪夫氏(Periodic Acid-Schiff, PAS)染色法比较4%多聚甲醛固定液、4%戊二醛固定液和Davidson 固定液固定豚鼠眼球的固定效果,筛选最佳眼球固定液和固定时间。

方法： 取正常豚鼠眼球分6组,每组5只,I组眼球放入4%多聚甲醛固定液固定24h、Ⅱ组眼球放入4%戊二醛固定液固定24h; Ⅲ～V组眼球放入Davidson 固定液分别固定3、6、24h; Ⅵ组眼球在Davidson 固定液中固定3h后转移到10%中性甲醛中再固定48h。常规制片、PAS染色、显微镜观察,比较不同固定方法对组织的固定效果。

结果：Davidson 固定液固定3h的固定效果最为理想,Davidson 固定液固定3h后转移到10%中性甲醛再固定48h的固定效果与Davidson 固定液固定3h的固定效果接近,这两组固定液固定的眼球切片均结构完整、层次清晰,视网膜各层细胞排列整齐。

结论： Davidson固定液对豚鼠眼球的固定效果明显优于其他两种固定液,豚鼠眼球用Davidson 固定液固定后,可将其转移到中性甲醛中长期保存,其固定效果不受影响。     

青光眼视网膜神经节细胞凋亡的实验研究

目的 研究兔的实验性青光眼视网膜神经节细胞的死亡是否有凋亡参与。方法 前房注入固定的红细胞悬液使免眼压升高,分别在术后７,１４,２１,２８天处死动物,取视网膜组织,ＴＵＮＥＬ标记染色,电镜观察。结果 电镜下可见视网膜神经节细胞死亡特征为典型的凋亡早期特征－核浓染。免疫组ＴＵＮＥＬ法实验组发现神经节细胞凋亡,而正常对照组没有发现。结论 实验性青光眼的视网膜神经节细胞死亡有凋亡参与。这为通过调探凋亡而治疗青光眼的视网膜视神经损伤提供可能。     

兔眼视网膜下注射N-甲基右旋天冬氨酸诱导视网膜变性的组织病理学研究

目的研究视网膜下注射兴奋性氨基酸N-甲基右旋天冬氨酸（NMDA）对神经细胞变性的作用。方法取12只1个月龄有色家兔,视网膜下注射10μl（30mmol／L）NMDA（溶剂为DMEM-F12）,形成视网膜隆起,在注射12、24、48h及1周后分别处死家兔,取其视网膜组织进行免疫组织化学检测和电镜观察。应用抗Calretinin、Calbindin、PKCα抗体,分别标记视网膜无长突细胞、水平细胞及视杆双极细胞;采用原位缺口末端标记技术（TUNEL）技术标记凋亡细胞。结果损伤早期（12～24h）,实验组视网膜可见散在细胞核固缩浓染的光感受器细胞,并有无长突细胞和神经节细胞的早期严重变性;中期（48h）视网膜各层神经元均出现病理性改变;损伤晚期（1周）视网膜各层细胞数目明显减少。损伤早期,TUNEL技术标记的阳性细胞位于视网膜各层。免疫组织化学和形态学计量资料显示视网膜下注射NMDA后,水平细胞、无长突细胞及神经节细胞数目明显减少,视杆双极细胞数目基本无变化。超微结构观察显示有凋亡、坏死、水肿变性及混合型细胞死亡等多种变性形式。结论视网膜下聚集NMDA时,光感受器细胞、水平细胞、视杆双极细胞、无长突细胞及神经节细胞均表现为视网膜兴奋性毒性反应,与以往体内及体外研究结果显示的仅有内核层神经元死亡情况不同。     

Dendritic differentiation in the periphery of the growing zebrafish retina

In the retina of teleost fish, new ganglion cells are generated from a circumferential peripheral growth zone at the edge of the eye throughout life. Addressing the question how new cells are fitted into the existing retina, we investigated newly formed ganglion cells in the zebrafish retina morphologically, by tracing them from the cut optic nerve with rhodamine dextran. We identified proliferating cells by antibody detection against proliferating cell nuclear antigen. In addition, newly formed bipolar cell and amacrine cell dendrites were investigated by antibodies against protein kinase C (PKC) and choline-acetyl-transferase (ChaT), respectively, and analyzed in sections or wholemount preparations using confocal microscopy. In retinal sections we observed that ganglion cell dendritic branches in the inner plexiform layer were in close apposition to dividing cells. In the periphery of retinal wholemounts, we detected rhodamine traced ganglion cells adjacent to the growth zone, extending dendrites in proximity to the growth zone, typically branching off in opposite directions running parallel to the retinal rim over more then 100 μm. Ganglion cells with similar dendritic branching patterns were not found in more central retinal areas. Similarly, the dendrites of ChaT-positive amacrine cells showed a preference for running parallel to the circumference in the periphery. Dendritic branches of PKC-positive bipolar cells did not show similar preferred orientation. The change in shape of the dendritic tree with distance from the periphery was studied for the Ma type ganglion cell. The data are consistent with the idea that existing ganglion cells might control differentiation of new ganglion cells. Moreover, ganglion cells with specific branching patterns towards the retinal periphery undergo a restructuring of their dendritic trees.     

A comparison of immunocytochemical markers to identify bipolar cell types in human and monkey retina

As more human retinas affected with genetic or immune-based diseases become available for morphological analysis, it is important to identify immunocytochemical markers for specific subtypes of retinal neurons. In this study, we have focused on bipolar cell markers in central retina. We have done single and double labeling using several antisera previously utilized in macaque monkey or human retinal studies and two new antisera (1) to correlate combinations of antisera labeling with morphological types of bipolar cells in human retina, and (2) to compare human labeling patterns with those in monkey retina. Human bipolar cells showed a wide range of labeling patterns with at least ten different bipolar cell types identified from their anatomy and marker content. Many bipolar cell bodies in the outer part of the inner nuclear layer contained combinations of protein kinase C alpha (PKC alpha), Islet-1, glycine, and Go alpha. Bipolar cells labeled with these markers had axons terminating in the inner half of the inner plexiform layer (IPL), consistent with ON bipolar cells. Bipolar cell bodies adjacent to the amacrine cells and with axons in the outer half of the IPL contained combinations of recoverin, glutamate transporter-1, and PKC beta, or CD15 and calbindin. Bipolar cells labeled with these markers were presumed OFF bipolar cells. Calcium-binding protein 5 (CaB5) labeled both putative ON and OFF bipolar cells. Using this cell labeling as a criteria, most cell bodies close to the horizontal cells were ON bipolar cells and almost all bipolar cells adjacent to the amacrine cells were OFF with a band in the middle 2-3 cell bodies thick containing intermixed ON and OFF bipolar cells. Differences were found between human and monkey bipolar cell types labeled by calbindin, CaB5, and CD15. Two new types were identified. One was morphologically similar to the DB3, but labeled for CD15 and CaB5. The other had a calbindin-labeled cell body adjacent to the horizontal cell bodies, but did not contain any accepted ON markers. These results support the use of macaque monkey retina as a model for human, but caution against the assumption that all labeling patterns are identical in the two primates.     

视网膜石蜡切片法改进及其分子结构与PMI关系的研究

目的：寻找一种更好的制作视网膜石蜡切片方法,探讨不同时间点视网膜层细胞凋亡蛋白Bax表达含量变化与死亡时间的关系。 方法：将Wistar大鼠按死后0,12,24,36h随机分为A,B,C,D四组,各组的眼球标本应用本研究新型改进方法制作石蜡切片后,分别做HE、免疫组织化学、荧光染色;进行图像分析与统计学处理。 结果：采用改进的石蜡切片制作方法,HE染色显示死后0h各组视网膜组织结构和层次均基本保持完整, 细胞形态清晰;随着时间的延长,视网膜各层逐渐发生紊乱并出现核固缩。免疫组织化学、免疫荧光染色结果均显示随着死亡时间的延长,A、B、C三组Bax表达含量依次增多,D组下降。两两比较,差异有统计学意义（P<0.05）。 结论：改进的石蜡视网膜组织切片制作方法较好,值得推广。Wistar大鼠死后不同时间视网膜层细胞凋亡蛋白Bax表达与死亡时间具有相关性,为法医进一步推断死亡时间的研究奠定了基础。"     

Immunocytochemical localization of excitatory and inhibitory neurotransmitters in the zebrafish retina.

The patterns of glutamate, gamma-aminobutyric acid (GABA), and glycine distribution in the zebrafish retina were determined using immunocytochemical localization of antisera at the light-microscope level. The observed GABA immunoreactivity (GABA-IR) patterns were further characterized using antibodies to both isoforms of glutamic acid decarboxylase (GAD65 and GAD67), the synthetic enzyme for GABA. Glutamate-IR was observed in all retinal layers with photoreceptors, bipolar cells, and ganglion cells prominently labeled. Bipolar cells displayed the most intense glutamate-IR and bipolar cell axon terminals were clearly identified as puncta arranged in layers throughout the inner plexiform layer (IPL). These findings suggest the presence of multiple subtypes of presumed OFF- and ON-bipolar cells, including some ON-bipolar cells characterized by a single, large (9 microm X 6 microm) axon terminal. GABA-, GAD-, and glycine-IR were most intense in the inner retina. In general, the observed labeling patterns for GABA, GAD65, and GAD67 were similar. GABA- and GAD-IR were observed in a population of amacrine cells, a few cells in the ganglion cell layer, throughout the IPL, and in horizontal cells. In the IPL, both GABA- and GAD-IR structures were organized into two broad bands. Glycine-IR was observed in amacrine cells, interplexiform cells, and in both plexiform layers. Glycine-positive terminals were identified throughout the IPL, with a prominent band in sublamina 3 corresponding to an immunonegative region observed in sections stained for GAD and GABA. Our results show the distribution of neurons in the zebrafish retina that use glutamate, GABA, or glycine as their neurotransmitter. The observed distribution of neurotransmitters in the inner retina is consistent with previous studies of other vertebrates and suggests that the advantages of zebrafish for developmental studies may be exploited for retinal studies.     

Localization of neurotransmitters and calcium binding proteins to neurons of salamander and mudpuppy retinas

We wished to identify the different types of retinal neurons on the basis of their content of neuroactive substances in both larval tiger salamander and mudpuppy retinas, favored species for electrophysiological investigation. Sections and wholemounts of retinas were labeled by immunocytochemical methods to demonstrate three calcium binding protein species and the common neurotransmitters, glycine, GABA and acetylcholine. Double immunostained sections and single labeled wholemount retinas were examined by confocal microscopy. Immunostaining patterns appeared to be the same in salamander and mudpuppy. Double and single cones, horizontal cells, some amacrine cells and ganglion cells were strongly calbindin-immunoreactive (IR). Calbindin-IR horizontal cells colocalized GABA. Many bipolar cells, horizontal cells, some amacrine cells and ganglion cells were strongly calretinin-IR. One type of horizontal cell and an infrequently occurring amacrine cell were parvalbumin-IR. Acetylcholine as visualized by ChAT-immunoreactivity was seen in a mirror-symmetric pair of amacrine cells that colocalized GABA and glycine. Glycine and GABA colocalized with calretinin, calbindin and occasionally with parvalbumin in amacrine cells.     

地塞米松对玻璃体积血兔视网膜病理变化的影响

目的:观察地塞米松(dexamethasone,Dxm)对兔玻璃体积血后视网膜病理变化的影响。方法:白兔24只,随机分为实验对照组(A),积血组(B)和Dxm干预组(C),每组8只。A组玻璃体内注入生理盐水0.2mL,B组、C组玻璃体内注入自体血0.2mL;注入后1,24,48h,A和B组给予生理盐水3mL/kg,C组给予Dxm3mg/kg。分别于造模后3,7,14,21d随机处死每组中的2兔4眼观察视网膜病理变化。结果:A组所有时间点,B组3,7d,C组3,7,14d视网膜形态正常。B组14d神经节细胞、内丛状层水样变性;21d视网膜内界膜不完整,内、外核层细胞和光感受器内、外节水样变性。C组21d神经节细胞染色变淡,内丛状层、内核层水样变性。结论:玻璃体积血可引起视网膜细胞水样变性,Dxm可缓解玻璃体积血后视网膜水样变性。     

Complex neurodegeneration in retina following moderate ischemia induced by bilateral common carotid artery occlusion in Wistar rats

Bilateral common carotid artery occlusion (BCCAO) produces moderate levels of ischemia in the retina of rats, which may simulate the inflow disturbances in severe carotid artery disease. ERG changes following acute BCCAO have been well described, but the effects of chronic BCCAO on the histopathology of the retina remain to be characterized in a reproducible model. Chronic BCCAO was induced in halothane-anaesthetized male Wistar rats and the retina fixed after 3, 6, or 24 hr, 1 week, and 2, 4, or 6 months. Cell counts and measurements of retinal layers were performed in H&E stained paraffin sections. Immunohistochemistry with a panel of fourteen antibodies served to examine the survival of different retinal cell class, astrocytic reactions and the expression of acute stress response proteins. A lectin method was used to label activated microglial cells. Microglial activation, heme oxygenase-1 upregulation and caspase-3 cleavage occurred during the first 24hr in the absence of overt cell death of retinal ganglion cells (RGC). Three waves of neurodegeneration followed. RGCs were affected after 1 week, followed by neurons in the inner nuclear layer at 2 months, and finally photoreceptors at 4 months. Immunomarkers indicated acute damage to horizontal cells and prolonged survival of amacrine cells. In conclusion, chronic BCCAO produced delayed neuronal death in the retina of adult male Wistar rats. The window of moderate changes of at least 1 day may facilitate molecular studies on retinal ganglion cell loss.