缺血再灌注损伤对大鼠视网膜功能的影响

目的 探讨缺血再灌注损伤对大鼠视网膜功能的影响。 方法 70只健康 Wistar 大鼠，预实验随机抽取 20 只分为正常对照组和单纯灌注组，记录视网膜电图（electroret inography，ERG）并测定b波峰值，经统计学处理无差异后，其余50只随机分为10组，用升高眼压1 h 的方法建立右眼视网膜缺血模型，分别于缺血后1 h及再灌注3、6、12 、24 h、3、5、7、14、21 d记录双眼暗视闪光 ERG并测定b波峰值。 结果 正常对照组动物左右眼ERG b波峰值无差异；单纯灌注眼与正常对照眼ERG b波峰值无差异；单纯缺血组实验眼ERG各波消失，再灌注实验眼组ERG b波部分恢复，但随再灌注时间的延长b波峰值呈进行性下降. 结论 视网膜缺血再灌注损伤可导致大鼠视网膜功能持续渐进性的影响。（中华眼底病杂志，2003，19：201-268）     

腺病毒载体介导的色素上皮衍生因子对大鼠视网膜缺血再灌注损伤后视觉电生理的影响

目的:观察重组腺病毒介导的色素上皮衍生因子(Ad-PEDF)对大鼠视网膜缺血再灌注损伤后视网膜电流图的影响。方法:选用健康大鼠24只,随机分为正常组、缺血再灌注组、缺血再灌注+Ad-CMV组,缺血再灌注+Ad-PEDF组,以前房加压的方法制备大鼠视网膜缺血再灌注模型,缺血再灌注+Ad-CMV组,缺血再灌注+Ad-PEDF组分别玻璃体腔注射Ad-CMV或Ad-PEDF1μL(滴度3.8×109/PFU),每组按照时间点12,24,72,168h分为4亚组,以ERG分别测量双眼各时期ERGb波、Ops波波幅。结果:缺血再灌注后ERGb及Ops波幅明显降低,与正常组相比在各时间点有明显的统计学差异,缺血再灌注组ERGb波及Ops波幅24h降低最为明显,与缺血12,72,168h相比差异具有显著性。AD-PEDF能够明显促进ERGb波及Ops波幅恢复,与缺血组、缺血再灌注+AD-CMV在各时间点均有明显统计学差异。结论:腺病毒介导的色素上皮衍生因子玻璃体腔注射能够促进大鼠视网膜缺血再灌注损伤功能恢复。     

热休克反应对大鼠视网膜缺血再灌注损伤的防御作用

目的 观察热休克反应对大鼠视网膜缺血再灌注损伤的防御作用。 方法 将20只Wistar大鼠20只眼随机分为4组，每组5只大鼠。行前房灌注（perfusion）平衡盐溶液制造急性高眼压模型,为高眼压组(P组)；在制造急性高眼压模型前24 h向大鼠腹腔内注射槲皮素(quercetin) (400 mg/kg)，为高眼压＋槲皮素组(P+Q组)；在制造急性高眼压模型前24 h 热休克(heat shock)大鼠，为高眼压＋热休克组(P+H组)；分别在制造急性高眼压模型前48 、24 h，向大鼠腹腔内注射槲皮素、热休克大鼠，为高眼压＋槲皮素+热休克组(P+Q+H组) 。按照国际临床视觉电生理学会的标准化方案，采用国特医疗系统对热休克反应后实验性高眼压大鼠模型和HSP70被槲皮素特异性抑制后实验性高眼压大鼠模型进行暗适应视网膜电图(dark adapted electroretinogram, D-ERG)、振荡电位(oscillatory potentials, OPs)和明适应E RG(light adapted ERG, L-ERG)记录。采用Western blotting方法检测各组大鼠视网膜HSP 70表达情况。 结果 P+H组大鼠视网膜HSP70表达在各组大鼠中最高，P+Q、P+Q+H组大鼠视网膜HSP70表达受到抑制。前房灌注后各组大鼠ERG各波潜伏期延长、幅值减小，P+H组D-ERG的b波、OPs的O₂波的幅值较P组高。灌注0 h后，P+H组各波幅值显著增高(P值均<0.05)；灌注24 h 后，P+H组大鼠视网膜功能恢复较P组好。P+Q、P+Q+H组大鼠灌注后ERG各波及OPs的O₂波潜伏期最长，幅值最低，甚至消失。 结论 热休克反应可以提高大鼠视网膜细胞对缺血再灌注损伤的防御作用。 （中华眼底病杂志，2003，19：117-120）     

缺血预处理对大鼠视网膜缺血再灌注损伤保护作用

目的：探讨缺血预处理是否对视网膜缺血再灌注损伤有保护作用及其机理,方法：利用前房灌注生理盐水形成高眼压的视网膜缺血再灌注损伤的动物模型,视网膜缺血时间为1h分别于缺血前30min、24h或72h对大鼠一只眼5min短暂缺血即预处理,24h或72h后行视网膜电图（ERG）、电镜、光镜、丙二醛（MDA）及热休克蛋白70（HSP70）检测,或者一侧眼行5min假处理,24h后行1h缺血,24h或72h再行上述检测,所有对侧眼不作处理作对照,结果：与假处理相相比,缺血前24、72h进行预处理后的大鼠视网膜光镜、电镜表现损害明显减轻,ERGb波明显恢复（P＜0．01）,MDA含量降低（P＜0．01）,缺血前30min预处理的视网膜表现严重的损害,ERGb波几安全消失,结论：缺血预处理对视网膜缺血再灌注损伤有保护作用,且有一定时限性。     

外源性神经生长因子对大鼠视网膜缺血再灌注损伤的保护作用

目的探讨外源性神经生长因子对大鼠视网膜缺血再灌注损伤的保护作用.方法建立结扎颈总动脉的大鼠视网膜缺血再灌注模型,分缺血再灌注组、缺血再灌注+外源性神经生长因子组.每组按再灌注时间的不同分为缺血再灌注1、6、12、24、48、72 h组.同时记录各期大鼠视网膜电图(electroretinogram,ERG)a、b波波幅,通过透射电镜观察各期视网膜的超微结构.结果缺血再灌注+外源性神经生长因子组各时期ERGa、b波波幅高于缺血再灌注组.视网膜超微结构显示缺血再灌注+外源性神经生长因子组细胞受损情况明显好于缺血再灌注组.结论外源性神经生长因子对大鼠视网膜缺血再灌注损伤具有保护作用.     

己酮可可碱对大鼠急性高眼压性视网膜缺血再灌注损伤的保护作用

目的:探讨己酮可可碱对大鼠视网膜缺血再灌注损伤的保护作用及机制。方法:视网膜缺血再灌注模型是通过提高前房眼内压来实现的。将35只Wistar大鼠随机分为3组:正常组5只,对照组15只,治疗组15只。治疗组于高眼压前6h和眼压正常后即刻己酮可可碱50mg/kgip,对照组于相同时间点等容量生理盐水ip。监测视网膜电流图(ERG)b波的变化,测定视网膜谷氨酸含量以及视网膜线粒体钙含量。结果:治疗组和对照组谷氨酸含量都在缺血再灌注后逐渐上升,在48h达到峰值,两组都明显高于空白对照组(P<0.01)。在6h点治疗组与对照组间无显著差异,在其他时点对照组的Glu含量明显高于治疗组(P<0.05)。治疗组和对照组视网膜线粒体钙含量在缺血再灌注后逐渐上升,在24h达到峰值,然后逐渐下降。两组都明显高于空白对照组(P<0.01)。在6h点治疗组与对照组间无显著差异,在其他时点对照组的视网膜线粒体钙浓度明显高于治疗组(P<0.05)。再灌注后,对照组ERGb波比较低平;再灌注后1h,对照组、治疗组的ERG相对b波无明显的差异。24h后两组b波都降低到最低,然后逐渐恢复;72h后对照组ERGb波仅恢复到正常眼的69%左右。己酮可可碱处理组ERGb波恢复到正常眼的95%左右,ERGb波明显较对照组高(P<0.01)。结论:己酮可可碱能有效降低视网膜谷氨酸含量及视网膜组织细胞线粒体钙离子含量,促进ERGb波的恢复,缩短了视网膜缺血再灌注的病理过程。对大鼠视网膜缺血再灌注损伤有一定的保护作用。     

米诺环素对大鼠视网膜缺血再灌注的保护作用探讨

目的 探讨米诺环索对大鼠视网膜缺血再灌注损伤的保护作用.方法 SD大鼠88只,分为正常对照组8只,缺血组和治疗组各40只.建立视网膜缺血再灌注模型,于6、24、48、72 h检测视网膜电图(ERG)b波振幅,分光光度计测定超氧化物歧化酶(SOD),丙二醛(MDA),一氧化氮(NO)的变化,免疫组织化学检测半胱天冬酶-3(caspase-3)的表达,电镜观察超微结构.结果 与缺血组相比,治疗组可维持ERG b波振幅,升高SOD含量,降低MDA、NO含量,降低caspase-3表达,可减轻超微结构损伤(P＜0.05).结论 米诺环素可维持ERG b波振幅,调控SOD、MDA、NO,改善超微结构而保护视网膜.     

盐酸氟桂嗪对家兔视网膜缺血—再灌注损伤保护作用的ERG观察

目的 动态观察盐酸氟桂嗪对家兔视网膜缺血－再灌注损伤的保护作用。方法 应用前房灌注加压法使前房内压力升高至16kPa。维持１h后再灌注,再灌注后第2、7、14天分别记录其ERG,与缺血前ERG相比,观察b波的变化。药物治疗组在造成缺血前12h,缺血－再灌注即刻及再灌注后12h静脉给予药物治疗。结果 药物治疗组ERG的b波与正常眼相比无明显差异。结论 盐酸氟桂嗪对视网膜缺血－再灌注损伤有保护作用。     

TNF-α在大鼠视网膜缺血再灌注损伤中的表达及NAC对其表达的影响

目的研究肿瘤坏死因子-α(tumornecrosisfactor-α,TNF-α)在大鼠视网膜缺血再灌注损伤中的表达及N-乙酰-L-半胱氨酸(N-acetylcysteine,NAC)对其表达的影响。方法结扎颈总动脉建立大鼠视网膜缺血再灌注模型,60只SD大鼠随机分为缺血再灌注组和缺血再灌注 NAC组。每组按再灌注后不同时间段分为1h、6h、12h、24h、48h、72h组,每组5只。以原位杂交法检测TNF-α的表达,每只大鼠处死前行视网膜电图(ERG)检测,并计算出左/右眼ERG的比值。结果缺血再灌注组在6h开始检测到TNF-α的表达,在24h表达最强,以后逐渐减弱。缺血再灌注 NAC组在再灌注6h未能检测到TNF-α的表达,在第12h有TNF-α的表达,24h表达最强,但低于缺血再灌注组(P<0·05)。缺血再灌注组在再灌注6h后各期ERG相对恢复率明显低于缺血再灌注 NAC组(P<0.05)。结论NAC可能通过抑制TNF-α在视网膜缺血再灌注损伤中的表达而起保护作用。     

七叶甙对大鼠缺血再灌注损伤视网膜电图的影响

目的 :观察七叶甙对视网膜缺血再灌注损伤模型视网膜电图 (ERG)的影响。方法 :结扎大鼠左颈总动脉 1h ,然后再灌注 ,同时向腹腔注射七叶皂甙钠及异搏定 ,比较再灌注后 1h、6h、12h、2 4h、4 8h、72h视网膜ERG的变化。结果 :再灌注 6h后 ,七叶甙组、异搏定组视网膜的ERG与生理盐水组相比 ,有明显的提高 ,而七叶甙组和异搏定组相比 ,无明显的差异。结论 :七叶甙可以促进缺血再灌注损伤视网膜ERGb波的恢复     

大鼠视神经部分切断模型的建立和重复性评价

 目的 应用自行设计的模具制作大鼠视神经部分切断模型,并评价大鼠视神经部分切断模型的可重复性。 设计 实验研究。研究对象  15只Wistar大鼠。方法  利用模具将大鼠视神经部分切断,术后对13只大鼠行荧光金逆行标记及全视网膜拼图,使用Ret-camⅡ眼底照相观察视网膜血供情况。主要指标  观察视网膜神经节细胞（RGC）形态及分布变异。结果 视神经部分切断直接影响的视网膜与周围正常视网膜有明确分界线,标记荧光金视网膜面积比例变异系数最大值为1.85%,平均变异系数为0.67%±0.44%。Ret-camⅡ眼底照相显示视神经部分切断后,未引起视网膜供血障碍。 结论 利用新型模具器械可成功建立易于量化的重复性高的RGC继发性损伤模型。（眼科,2013,22：34-37）     

Protective effect of LIF-huMSCs on the retina of diabetic model rats

AIM: To investigate the protective effect of human umbilical cord mesenchymal stem cells (hUCMSCs) modified by the LIF gene on the retinal function of diabetic model rats and preliminarily explore the possible mechanism. METHODS: A stably transfected cell line of hUCMSCs overexpressing leukemia inhibitory factor (LIF) was constructed. Overexpression was verified by fluorescent quantitative polymerase chain reaction (qPCR). Forty-eight adult Sprague-Dawley rats were randomly divided into a normal control group (group A), streptozotocin-induced diabetic control group (group B), diabetic rats at 3mo injected with empty vector-transfected hUCMSCs (group C) or injected with LIF-hUCMSCs (group D). Four weeks after the intravitreal injection, analyses in all groups included retinal function using flash electroretinogram (F-ERG), retinal blood vessel examination of retinal flat mounts perfused with fluorescein isothiocyanate-dextran (FITC-dextran), and retinal structure examination of sections using hematoxylin and eosin staining. Expression levels of adiponectin (APN), high-sensitivity C-reactive protein (hs-CRP), and neurotrophin-4 (NT-4) in each group was detected using immunohistochemistry, PCR, Western blotting, and ELISA, respectively. RESULTS: A stable transgenic cell line of LIF-hUCMSCs was constructed. F-ERG and FITC-dextran examinations revealed no abnormalities of retinal structure and function in group A, severe damage of the retinal blood vessels and function in group B, and improved retinal structure and function in group C and especially group D. qPCR, ELISA, and Western blot analyses revealed progressively higher APN and NT-4 expression levels in groups B, C, and D than in group A. hs-CRP expression was significantly higher in group B than in groups A, C, and D, and was significantly higher in group C than in group D (P<0.05). CONCLUSION: LIF-hUCMSCs protect the retina of diabetic rats by upregulating APN and NT-4 expression and downregulating hs-CRP expression in the retina.     

Measurement of retinal function with flash-electroretinography in Chinese patients with hyperlipidemia

Background

We used flash electroretinography (F-ERG) to determine if retinal function was impaired in patients with hyperlipidemia, including visual acuity and fundus morphological changes, and to identify predictors of impaired retinal function in hyperlipidemia patients.

Methods

This was a prospective case–control study (Shanghai, China; February 2011 to January 2012) in 696 hyperlipidemia patients and 136 healthy controls. Exclusion criteria included best-corrected visual acuity <0.6, previous intraocular surgery, and chronic comorbidities. Each participant underwent a comprehensive series of ophthalmologic examinations, and standard F-ERG examination. Data were analyzed using t-tests and multivariate analysis.

Results

Six hundred and twenty-six hyperlipidemia patients (57.69?±?14.01 years; 59.58 % female) and 120 healthy controls (55.13?±?14.03 years; 60 % female) were included in the final analysis. After adjustment for age and gender using multivariate covariance analysis, F-ERG result revealed significantly lower response amplitudes in the hyperlipidemia group (P?P?P?P?P?P?=?0.03) were negatively correlated with ΣOps.

Conclusion

The present study suggests that the retinal function of hyperlipidemia patients was significantly lower than in healthy controls, even before the occurrence of pathological changes in the fundus.     

正常成年家猫不同明适应条件下闪光视网膜电图的变化

目的:探讨正常成年家猫不同明适应条件下闪光视网膜电图(flash electtoretinogram,F-ERG)最大反应的变化并建立正常值范围,为相关研究提供一种创伤较小且实用可行的实验方法和相关依据.方法:成年家猫37只,全麻状态下暗适应20min后开启背景光计时,在明适应5,15,30,60s;3,5,10,20,30min用相同强度的光刺激、采集并记录分析不同明适应时间点F-ERG的a,b波的峰潜时及振幅并描出a,b波的振幅变化曲线图.结果:在不同明适应时间成功记录到典型且重复性好的F-ERG波形.经过分析观察到在不同的明适应时间,a,b波的潜伏期均无明显差异,b波的振幅变化较为明显,明适应5min后记录到的F-ERG,b波振幅值达高峰.结论:本法为成年家猫明适应F-ERG的检测提供了一种创伤小且具有较好重复性的实验方法和实验参考依据.     

视网膜电图在视网膜分支静脉阻塞分型中的应用价值

目的探讨根据视网膜电图(electroretinogram，ERG)对视网膜分支静脉阻塞(branch retinal vein occlusion，BRVO)分型的可能性。方法根据眼底荧光血管造影(fundus fluorescein angiography，FFA)将BRVO分为缺血型及非缺血型，同时行ERG检查，测a、b波振幅、峰潜时及b/a波振幅比值和振荡电位：OP₁、OP₂、OP₃、OP₄振幅、峰潜时及OP₁+OP₂+OP₃+OP₄的振幅之和OPs波的振幅。结果BRVO缺血型组b波及OPs振幅明显下降，缺血组与非缺血型组之间有显著差异。结论ERGb波及OPs振幅下降可作为缺血型的一项参考指标。(中华眼底病杂志,1998,14:10-11)     

高血压性视网膜病视网膜电图表现的研究

目的 研究高血压性视网膜病患者的视网膜电图表现,了解高血压对视网膜的损害及视网膜功能的改变。方法 对高血压组２８例５２眼,年龄３８～８６岁;对照组１７例２５眼,年龄为２４～６５岁;采用暗适应视网膜电流描计法分别记录其ＯＰｓ和ｂ波振幅。结果在高血压组中,ＯＰｓ和ｂ波振幅均较对照组明显降低并随年龄的增大而变得更加明显。与ｂ波振幅相比,ＯＰｓ的变化更大,即ＯＰｓ和ｂ波对高血压引起的视网膜的改变更敏感。结论 结果表明,ＯＰｓ和ｂ波振幅在评价视网膜小血管高血压性改变上是一种客观而有用的指标,对应用了近一个世纪的检眼镜将是有益的补充和发展。     

Loss of retinal ganglion cells following retinal ischemia: the role of inducible nitric oxide synthase

Following experimental, transient, retinal ischemia in the rat, there is loss of retinal neurons, which occurs over several weeks. Retinal ganglion cells (RGCs) are particularly susceptible and there is early, massive degeneration of these neurons after ischemia. We have determined the early mechanisms by which RGCs are killed following ischemia. Retinal ischemia/reperfusion was produced in rats by transient unilateral elevation of intraocular pressure above systolic blood pressure. Retinas were studied by immunohistochemistry for the presence of inducible nitric oxide synthase (NOS-2) at several time points post-ischemia and specific cell types were identified. Rats were also treated orally with L -N(6) -(1-iminoethyl)lysine 5-tetrazole amide (SC-51), a prodrug of an inhibitor of NOS-2 or with aminoguanidine (AG) for a period of 14 days. Retrograde labelling with Fluoro-Gold quantitated the loss of RGCs. NOS-2 was not present in the normal retina and was not present in the eyes that were contralateral to the ischemic eyes. Within 24hr after ischemia, polymorphonuclear leukocytes containing NOS-2 had entered the ganglion cell layer and surrounded RGCs. Within 5 days after ischemia, NOS-2 was present in many inner retina cells and in invading monocytes in the vitreous. Between 7 and 14 days post-ischemia, there were few hematogenous cells in the retina but NOS-2 was sparsely detectable in microglia and other cells of the inner retina. Two weeks after ischemia, rat eyes lost approximately 50% of the RGCs. Treatment with AG for 14 days following ischemia was partially neuroprotective; approximately 28% of the RGCs were lost. Treatment with SC-51 for 14 days following ischemia almost completely prevented the loss of RGCs. Thus, within 24hr following ischemia, polymorphonuclear leukocytes containing NOS-2 attack and kill neurons in the ganglion cell layer. For 2 weeks after ischemia, NOS-2 appears transiently in the retina in several different cell types at different times. Continuous pharmacological treatment with inhibitors of NOS-2 activity during the 2 weeks post-ischemia period provides significant neuroprotection against the loss of RGCs.     

利拉鲁肽在早期糖尿病视网膜病变中的视网膜神经保护作用

目的：研究胰高血糖素样肽-1(glucagon-like peptide-1,GLP-1)类似物(利拉鲁肽)对轻、中度非增生期糖尿病视网膜病变(nonproliferative diabetic retinopathy,NPDR)患者的视网膜神经保护作用的临床疗效。

方法：收集于我院内分泌科治疗的2型糖尿病合并轻、中度NPDR的患者60例。随机分为两组,试验组患者使用二甲双胍、胰岛素联合利拉鲁肽降血糖,对照组使用二甲双胍、胰岛素降血糖。比较两组患者治疗前和治疗后6mo糖化血红蛋白、图形视觉诱发电位(pattern visual evoked potential, P-VEP)的P100波幅值和P100潜伏期、全视野闪光视网膜电图(full field electroretinogram,F-ERG)的震荡电位(oscillatory potentials,Ops)总波幅值和明、暗适应3.0的a波、b波的振幅变化。

结果：治疗后6mo,试验组和对照组Ops总波幅值较治疗前均增加(均P<0.01),试验组Ops总波幅较对照组高(P=0.049)。治疗后试验组患者的明、暗适应3.0的b波振幅较对照组高(P=0.001、0.014); 但是治疗后两组患者糖化血红蛋白值、明、暗适应3.0的a波振幅无差异(P=0.505、0.441、0.193)。治疗后试验组明、暗适应3.0的b波振幅较治疗前增加(P<0.01、P=0.019),明、暗适应的a波振幅较治疗前增加,然而差异无统计学意义(P=0.130、0.147)。

结论：利拉鲁肽可以一定程度上改善轻、中度NPDR患者的视网膜神经细胞的功能,对DR的预后有着积极的作用。     

Role of alpha-2 agonists in neuroprotection

Four criteria are used to evaluate the potential usefulness of an agent for neuroprotection in glaucoma: 1) the agent must have a target in the retina; 2) it must be neuroprotective in animal models; 3) it must reach neuroprotective concentrations in the posterior segment after clinical dosing; and finally, 4) it must be shown to be neuroprotective in clinical trials. The alpha-2 adrenergic agonist brimonidine has met the first three criteria and clinical trials to establish the fulfillment of the fourth criterion are ongoing. The effects of brimonidine are mediated by its interaction with alpha-2 adrenergic receptors that are present in the retina. Activation of alpha-2 receptors by brimonidine has been shown to effectively promote the survival and function of retinal ganglion cells in a variety of animal models of optic injury relevant to glaucoma such as the chronic ocular hypertensive rat and rat optic nerve crush. Brimonidine has also been shown to be neuroprotective in the rat ischemia reperfusion model that evaluates general hypoxic damage to the whole retina. Clinical dosing of the topical formulation of brimonidine results in brimonidine concentrations in the posterior segment that are sufficient for both pharmacological activity at alpha-2 adrenergic receptors and neuroprotection. Finally, clinical trials are in progress to investigate the ability of brimonidine to protect human retinal ganglion cells and the visual field in glaucoma-related disease.