实验性糖尿病小鼠视网膜电图振荡电位的变化

目的:探讨高血糖对糖尿病小鼠视网膜电图振荡电位(OP)的影响。方法:C57BL/6雄性小鼠80只分为正常组10只和糖尿病组70只。糖尿病组用STZ造模,4wk后将符合条件的小鼠纳入观察组。检测4,8,12,16,20wk时小鼠OP的表现。结果:在STZ诱导造模后,糖尿病组小鼠与对照组相比体质量增长明显降低,差异有明显统计学意义(P<0.05);建模后糖尿病组血糖明显高于对照组,差异有统计学意义(P<0.01);建模后4wk起,糖尿病小鼠视网膜电图OP1,OP2,OPs振幅有下降趋势,峰潜时延长,与对照组小鼠相比差有统计学意义(P<0.01);20wk时糖尿病小鼠OP1,OP2,OPs振幅降低,峰潜时延迟,与4wk时比较差异有统计学意义(P<0.01)。结论:高血糖可使糖尿病小鼠OP振幅下降,峰潜时延长;且随病程的延长其影响逐渐增强。     

高血糖对实验性糖尿病大鼠视网膜电图的影响

目的观察糖尿病大鼠ERG和OPs的变化情况,探讨糖尿病对大鼠FERG和OPs的影响。方法将100只大鼠分为正常组10只和糖尿病组90只。糖尿病组用STZ造模,6个月后将符合条件的大鼠纳入观察组。检测6、9个月时大鼠ERG和OPs的表现。结果糖尿病大鼠视网膜电图a波、b波、OPs振幅有下降趋势,峰潜时延长,与对照组大鼠相比有差异(P<0.01);9个月时糖尿病大鼠a波、b波、OPs振幅降低,峰潜时延迟,与6个月时比较有显著差异(P<0.01或0.05)。结论高血糖可使糖尿病大鼠ERG和OPs振幅下降,峰潜时延长;且随病程的延长其影响逐渐增强。     

糖尿病视网膜病变振荡电位和荧光血管造影的相关性

目的 :研究在荧光素钠血管造影 (FA)和吲哚青绿血管造影 (ICGA)下糖尿病视网膜病变 (DR)在不同阶段、形态改变时的振荡电位 (OPs) ,了解DR的功能学与形态学改变的特点及其之间的联系。方法 :选择 4 9名糖尿病患者(89只患眼 ) ,按在FA下DR的不同阶段分 4组 (88眼 ) ,按ICGA分 2组 (6 0眼 ) ,选择 4 3只正常眼为对照组 ,对所有眼按国际标准化方法进行OPs检测。结果 :OPs总和振幅在FA有改变时下降 ,OP2 振幅在FA无改变时下降 ,有改变时进一步下降 ;无灌注期与新生血管期的OPs总和振幅及各子波振幅改变相同 ;ICGA晚期 ,部分眼出现晚期弥散性高荧斑和极晚期高荧伴低荧的“椒盐状”外观 ,与此相应 ,OP3 振幅和OP4潜伏期较对照组下降和延长。结论 :OP2 振幅较OPs总和振幅在DR早期诊断方面敏感 ,无灌注期和新生血管期的视网膜循环状态相似 ,无灌注区可与新生血管一样作为DR进展的质变标志 ,ICGA后期改变与OPs的指标有一定联系     

Captopril抑制鼠视网膜新生血管形成的实验研究

目的 探讨 captopril对鼠视网膜新生血管形成的抑制作用.方法 将60只7 d龄小鼠随机分为对照组(30只)和治疗组(30只),置于体积分数75%高氧环境下饲养5 d后回到正常空气环境中饲养,出氧箱后治疗组每天1次玻璃体腔注射captopril(2.7 mL·kg-1),对照组注射生理盐水注射液(2.7 mL·kg-1),连续5 d.2组小鼠均于17 d时处死并摘除眼球,采用视网膜铺片、HE染色及免疫组织化学法分别观察视网膜血管的改变、计数视网膜新生血管内皮细胞核数并检测基质金属蛋白酶-2蛋白的表达.结果 治疗组与对照组相比视网膜血管分布规则、分支良好、新生血管密度减少,且突破视网膜内界膜的血管内皮细胞核数治疗组为(5.39±1.32)个,对照组为(30.43±0.55)个,治疗组明显少于对照组(P＜0.05);治疗组基质金属蛋白酶-2染色较对照组减弱.结论 玻璃体腔内注入captopril能够有效抑制高氧诱导下的小鼠视网膜新生血管形成,captopfil有望成为防治血管增生性视网膜病变的一种有效方法.     

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)     

坎地沙坦对糖尿病大鼠视网膜VEGF和MCP-1表达的影响

目的:研究血管紧张素Ⅱ受体拮抗剂坎地沙坦对糖尿病(DM)大鼠视网膜组织VEGF和MCP-1表达的影响。方法:链脲佐菌素(STZ)制备DM大鼠动物模型36只,随机分为DM模型组和坎地沙坦治疗组,另取18只正常SD大鼠作为正常对照组,每组均随机分为4,8,12wk3个亚组。视网膜铺片联合PAS染色观察视网膜微血管形态学变化,应用SABC免疫组织化学法检测坎地沙坦对大鼠视网膜组织VEGF和MCP-1表达的影响。结果:正常对照组视网膜血管网结构清晰,走行规则;DM模型组血管迂曲阻塞,走行不规则;治疗组见血管网迂曲情况较模型组明显改善,走行较规则。在对照组和模型4wk组中大鼠视网膜组织无VEGF和MCP-1阳性表达或只呈弱阳性表达;模型8wk和12wk组两者阳性表达明显增强,且随着病程延长呈递增趋势。治疗组两者的表达则均较同时期模型组明显减弱,差异有统计学意义(P<0.05)。结论:研究血管紧张素Ⅱ受体拮抗剂坎地沙坦可降低DM大鼠视网膜VEGF和MCP-1的表达。     

PTK787抑制早产儿视网膜病变大鼠模型新生血管的形成

目的探讨受体酪氨酸激酶亚群抑制剂PTK787对早产儿视网膜病变(retinopathy of prematurity,ROP)新生血管形成的抑制作用。方法建立波动氧(体积分数80%和10%氧浓度24h反复交替)诱导的SD大鼠ROP模型。67只新生SD大鼠随机设立对照组(22只)、模型组(22只)、治疗组(23只,腹腔注射PTK78750mg.kg-1);分别于第12天和第17天,每组随机抽取8只新生鼠,一侧眼球采用ADP酶组织化学法进行视网膜铺片,观察视网膜血管改变;另一侧眼球视网膜组织切片观察并计数突破视网膜内界膜的血管内皮细胞核数目。结果波动氧可成功诱导SD新生大鼠ROP模型,PTK787可抑制氧诱导新生鼠视网膜病变模型新生血管的形成。第12天和第17天时,模型组视网膜ADP酶组织化学铺片,均较对照组血管分布、密度改变明显;而治疗组视网膜铺片血管密度较模型组明显下降。第17天突破视网膜内界膜的血管内皮细胞核计数结果显示,给氧模型组31.360±4.543与正常对照组1.700±1.216比较,差异有显著统计学意义(t=-56.414,P<0.001)。治疗组6.800±2.107与模型组相比,血管内皮细胞核数显著减少(t=-43.869,P<0.001)。结论 PTK787可以抑制视网膜新生血管的形成,有望成为治疗ROP的有效途径。     

糖尿病早期大鼠视网膜功能的多焦视网膜电图研究

目的:建立高血糖动物模型并以多焦视网膜电图(mfERG)评价其早期视网膜功能状态。方法:SD大鼠16只,随机分为正常对照组和预造模组,采用化学药物链尿佐菌素(STZ)分2次ip,建立高血糖动物模型,观察2组大鼠一般性生理指标,并分别于成模后1,2,4,8wk末对其进行多焦视网膜电图检测。结果:STZ分次ip大鼠一次成模率80%,8wk死亡率12.5%,血糖始终保持在稳定的高水平;STZ大鼠1wk时N1波和P1波波峰潜时已有延长,反应密度降低,P1波改变较为明显,4wk时与正常组相比P<0.05,8wk时与正常组相比P<0.01。结论:STZ低剂量分次注射是较为理想的高血糖动物造模方法。糖尿病大鼠在1wk时即出现视网膜功能的损害,并随着高血糖状态的持续而逐渐加重,即在出现明显视网膜病变之前已经出现了视网膜功能损害。     

夜间光照对氧诱导的视网膜病变小鼠视网膜新生血管形成的影响

背景 氧诱导的视网膜新生血管形成是多种视网膜血管性疾病的病理学基础,预防视网膜新生血管的形成可缓解视网膜病变对视网膜的损害程度.研究表明夜间睡眠时给予光照可能对早期糖尿病视网膜病变(DR)患者有利,但其对早产儿视网膜病变(ROP)患者视网膜新生血管有无影响报道较少.目的 观察夜间光照对氧诱导视网膜病变(OIR)小鼠视网膜新生血管形成的影响.方法 将64只SPF级新生C57BL/6J小鼠按随机数字表法随机分为正常对照组、单纯夜间光照组、OIR模型组、OIR联合夜间光照组,每组16只小鼠.正常对照组和单纯夜间光照组小鼠生长于正常空气(氧体积分数21％);OIR模型组和OIR模型联合夜间光照组小鼠于出生后第7天置于高氧环境(75％±2％)生长,出生第12天调整氧体积分数为正常;OIR联合夜间光照组和单纯夜间光照组于出生后第12～17天给予夜间光照,光照度为100 Ix.各组小鼠均于出生后第17天摘除眼球,采用ADP酶法制备视网膜铺片,了解视网膜血管的改变情况;视网膜组织切片行苏木精-伊红染色并计数突破视网膜内界膜的新生血管内皮细胞核数;免疫组织化学法观察各组小鼠视网膜中血管内皮生长因子(VEGF)的表达,实时荧光定量聚合酶链反应(PCR)法检测各组视网膜中VEGFmRNA的表达.实验动物的使用和喂养遵循ARVO声明.结果 正常对照组和单纯夜间光照组小鼠视网膜血管形态均无明显差异.OIR模型组视网膜铺片显示视网膜中央部大片无血管区,大量结构异常的新生血管形成.与OIR模型组相比,OIR模型联合夜间光照组视网膜中央无血管区面积以及新生血管分布密度减少.在实验后第17天时,正常对照组和单纯夜间光照组视网膜新生血管内皮细胞核数分别为(0.97±0.83)个和(1.00±0.72)个,OIR模型组为(38.57±5.01)个,而OIR联合夜间光照组小鼠视网膜新生血管内皮细胞核数为(16.92±3.39)个,总体差异有统计学意义(F=78.767,P=0.000),OIR联合夜间光照组视网膜新生血管内皮细胞核数明显少于OIR模型组,差异有统计学意义(t=20.446,P＜0.01).免疫组织化学法检测显示OIR模型联合夜间光照组中VEGF蛋白表达明显少于OIR模型组.正常对照组、单纯夜间光照组、OIR模型组和OIR联合夜间光照组小鼠视网膜VEGF mRNA相对表达量分别为1.00±0.00、0.94±0.07、2.08±0.50和1.43±0.21,各组间的总体差异有统计学意义(F=11.268,P=0.003),OIR模型联合夜间光照组表达较OIR模型组下调,差异有统计学意义(t=20.163,P＜0.05).结论 夜间光照可减少OIR小鼠视网膜新生血管的形成.     

氧诱导小鼠视网膜新生血管的实验研究

目的 制作氧诱导视网膜新生血管的小鼠动物模型并了解其视网膜血管内皮生长因子(VEGF)的变化.方法将出生后第7 d的C57BL/6J小鼠置于75%的高氧环境中5 d,再置于普通空气中5 d.在空气中饲养的小鼠为对照组.两组进行视网膜铺片,ADPase染色,组织切片染色,ELISA测定视网膜VEGF蛋白含量.结果实验组新生血管形成率为100%,对照组未见新生血管.实验组小鼠生后第17 d时突破视网膜内界膜的血管内皮细胞核数目达(46.7±11.1)个,对照组不足2个.第12 d实验组视网膜VEGF蛋白水平比对照组下降,第17 d比对照组升高. 结论该动物模型是研究早产儿视网膜病变(ROP)发病机制及治疗的合适模型.VEGF是造成视网膜新生血管发生的主要机制之一.     

促红细胞生成素对早期糖尿病大鼠ERG的影响

目的:观察促红细胞生成素对早期糖尿病大鼠ERG影响。方法:将45只Wistar大鼠随机分成3组,即正常对照组、糖尿病模型组和EPO干预组,链尿佐菌素诱导糖尿病大鼠模型,6wk后测量ERGa波、b波及OPs潜伏期及波幅。结果:EPO干预组F-ERG a,b,OPs各子波OP1,OP2,OP3波峰值潜伏时与正常组比较无显著性意义(P>0.05),而与糖尿病模型组比较有显著性意义(P<0.05);EPO干预组F-ERG a,b波幅及OPs总波幅与糖尿病模型组比较有显著性意义(P<0.05)。结论:EPO对早期糖尿病大鼠视网膜病变具有防治作用。     

FLK-1单克隆抗体抑制实验性视网膜血管新生的实验研究

目的:观察血管内皮生长因子受体2(FLK-1)单克隆抗体(anti-FLK1mAb)对视网膜新生血管形成(retinal neovascularization,RNV)的抑制作用,同时分析其对缺血性视网膜病变的影响。方法:将生后第7d的C57BL/6幼鼠置于高氧箱中饲养5d后取回至正常空气环境诱导RNV模型,生后第12,13,15d利用腹腔注射的方法给与实验组小鼠anti-FLK1 mAb500μg(对照组给与等量的大鼠免疫球蛋白),生后第17d处死动物行视网膜铺片和免疫组织化学染色检查,测量视网膜血管无灌注区的面积,计数RNV内皮细胞核数目,定量分析anti-FLK1 mAb对于缺血性视网膜病变以及实验性RNV形成的影响。结果:对照组和实验组均成功建立了RNV模型,实验组RNV的形成明显受到抑制(P<0.01),同时anti-FLK1 mAb也加重了RNV模型的缺血过程(P<0.05)。结论:拮抗FLK-1可以有效抑制RNV的形成,提示拮抗FLK-1可能成为治疗RNV有效的生物学方法之一,其可能加重缺血性视网膜病变的潜在副作用需进一步探讨。     

贝伐单抗联合全视网膜光凝治疗增生型糖尿病视网膜病变的疗效观察

目的　检测贝伐单抗玻璃体内注射疗法（ｂｅｖａｃｉｚｕｍａｂｉｎｊｅｃｔｉｏｎｓｉｎｖｉｔｒｅｏｕｓ,ＩＶＢ）对增生型糖尿病视网膜病变（ｐｒｏｌｉｆｅｒａ-ｔｉｖｅｄｉａｂｅｔｉｃｒｅｔｉｎｏｐａｔｈｙ,ＰＤＲ）中视网膜新生血管（ｒｅｔｉｎａｌｎｅｏｖａｓｃｕｌａｒｉｚａｔｉｏｎ,ＲＮＶ）的消退作用;评估ＩＶＢ联合全视网膜光凝（ｐａｎ-ｒｅｎｔｉｎａｌｐｈｏｔｏｃｏａｇｕｌａｔｉｏｎ,ＰＲＰ）对ＰＤＲ的临床疗效和安全性。方法　本研究收集行ＰＲＰ的ＰＤＲ患者７２例（７２眼）,根据术前是否ＩＶＢ分为注射组和对照组,注射组在完成ＩＶＢ１．２５ｍｇ后第７天行眼底荧光血管造影（ｆｕｎｄｕｓｆｌｕｏｒｅｓｃｅｉｎａｎｇｉｏｇｒａｐｈｙ,ＦＦＡ）检查,并于当天开始第一个象限的ＰＲＰ,每周１次,共４次完成ＰＲＰ;对照组每周１次,共４次完成ＰＲＰ。两组患者均于ＰＲＰ后４周、８周、１２周复诊,并复查最佳矫正视力（ｂｅｓｔｃｏｒｒｅｃｔｅｄｖｉｓｕａｌａｃｕｉｔｙ,ＢＣＶＡ）、眼压、ＦＦＡ、光学相干断层扫描、眼前节及眼底。结果　注射组ＩＶＢ后１周,ＢＣＶＡ提高,ＲＮＶ渗漏面积减少,与治疗前差异有统计学意义（Ｐ＜０．０５）;注射组各时间点ＢＣＶＡ、ＲＮＶ消退情况均显著优于对照组（均为Ｐ＜０．０５）。注射组各时间点黄斑中心凹视网膜厚度均较治疗前显著下降（均为Ｐ＜０．０５）,对照组各时间点黄斑中心凹视网膜厚度均较治疗前显著降低（均为Ｐ＜０．０５）,两组之间各时间点比较,差异均无统计学意义（均为Ｐ＞０．０５）。结论　ＰＲＰ能延迟单纯ＩＶＢ后ＲＮＶ的复发;联合治疗可更有效地推动ＰＤＲ中ＲＮＶ消退,安全可靠,可以更好地保护患者的视觉功能。     

Development of the electroretinographic oscillatory potentials in normal and ROP rats

PURPOSE: To study the development of the electroretinographic (ERG) oscillatory potentials (OPs) in rats and to compare normal OPs with those in a rat model of retinopathy of prematurity (ROP). METHODS: Following a longitudinal design, ERG responses to a greater than 5 log unit range of full-field stimuli were recorded in dark-adapted rats at postnatal day (P) 18, P31, P47, and P67. The ERG records were digitally filtered (60-235 Hz), and the trough-to-peak amplitudes and implicit times of OP2, OP3, OP4, and OP5 were measured. Additionally, rats with oxygen-induced retinopathy, a model of ROP, were studied at P31. RESULTS: Generally, OP amplitude increased and implicit time decreased with increasing stimulus intensity. The shape of the stimulus-response functions changed with age. The amplitudes of OP2, OP3, and OP4 were largest at P31. OP5 was largest at P47. All OPs were significantly affected in ROP rats; OP5 was least affected by ROP. CONCLUSIONS: A prolonged normal course of OP development, which featured waxing and waning of amplitudes, was observed and might have been consequent to maturation and then to final refinements of inner retinal circuitry. In ROP rats, marked attenuation of early OPs was consistent with persistent dysfunction of photoreceptors, and significant attenuation of the late OP5 was evidence of compromised function of inner retinal circuitry.     

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。     

结膜下和玻璃体内注射重组人PEDF对氧诱导大鼠RNV的作用

目的:观察结膜下和玻璃体注射重组人色素上皮衍生因子(pigment epithelium-derived factor,PEDF)两种注射方式对氧诱导大鼠视网膜新生血管(retinal neovascularization,RNV)的作用。方法:新生大鼠2只进行左眼结膜下注射PEDF,Westernblot检测视网膜PEDF的表达。氧诱导SD新生大鼠建立类似早产儿视网膜病变动物模型。新生鼠48只随机分为6组(A:空气对照组,B:高氧对照组,C:高氧+玻璃体注射PEDF2μg组,D:高氧+结膜下注射PEDF2μg组,E:高氧+结膜下注射PEDF4μg组,F:高氧+结膜下注射PEDF8μg组)。当新生大鼠脱离氧时,C,D,E和F组大鼠左眼用不同剂量和注药次数进行注射PEDF,ADP酶视网膜血管染色观察视网膜血管形态,石蜡切片计数突破视网膜内界膜的新生血管内皮细胞核数目。结果:结膜下注射重组人PEDF,可检测到视网膜PEDF蛋白表达。视网膜铺片结果显示:A组视网膜血管发育正常;B组视网膜大量的新生血管生成;C组新生血管明显减少;D,E,F组新生血管稍减少。组织病理学检测突破视网膜内界膜的新生血管内皮细胞计数可见:A组视网膜内界膜平滑,偶见突破的视网膜内皮细胞。B组明显高于A组,差异有统计学意义(P<0.05)。C组明显低于B组(P<0.05),D,E,F组与C组差异有统计学意义(P<0.05)。结论:巩膜和脉络膜-色素上皮层对PEDF是有渗透性的,可以跨越结膜下组织到达视网膜,但与玻璃体注射组相比,抑制新生血管作用有显著减弱;玻璃体注射可有效抑制氧诱导大鼠RNV。     

Inhibitory effect of captopril on retinal neovascularization in mice

AIM: To study the inhibitory effect of captopril on retinal neovascularization (RNV). METHODS: Sixty seven-day-old mice were randomly divided into treated group and control group with thirty mice in each group. These mice were exposed to 750 ± 50mL/L oxygen for 5 days and then to room air. The treated group had been injected captopril (2.7mL/kg), while control group had been injected 9g/L sodium chloride (2.7mL/kg) by intravitreal for 5 days. The mice were sacrificed at the 17th day after birth and the eyes were enucleated. Adenosine diphosphate-ase (ADPase) stained retina flat-mounts was performed to assess the retinal vascular profiles, Hematoxylin Eosin (HE) staining method was applied to count the number of new vascular cell nuclei and the expression of matrix metalloproteinase-2 (MMP-2) and pigment epithelium derived factor (PEDF) was detected by immunohistochemical method. · RESULTS: Comparing with control group, regular distributions, good branch and reduced density of RNV were observed in the treated group. The number of nucleus of new vessels vascular endothelial cells breaking through the internal limiting membrane was less in the treated group than in the control group ( <0.05). Stain of retinal MMP-2 was weaker in the treated group than in the control group and stain of retinal PEDF was stronger in the treated group than in the control group. CONCLUSION: Intravitreal injection of captopril (2.7mL/kg) may block the RNV in the oxygen-induced mouse model and the method may provide an effective method for preventing RNV.     

Oscillatory potential analysis and ERGs of normal and diabetic rats

PURPOSE: To identify and characterize the early alterations of the ERG oscillatory potentials (OPs) under conditions of poor glycemic control associated with diabetes in an animal model. To characterize and correlate the a- and b-wave properties of the ERGs of diabetic animals in parallel with the changes in oscillatory potentials. METHODS: Blood sugars, weights, and ERGs were measured for a group of rats each week for 3 weeks to obtain baseline information. A single injection of streptozotocin was given to the experimental animals. Weights, blood sugar, glycosylated hemoglobin, and detailed ERGs were recorded weekly for up to 12 weeks in control and experimental animals. RESULTS: OP kinetics were found to be inherently related to amplitude. Amplitude-matched OPs were delayed in diabetic animals when compared with baseline data from the same animal. The kinetics of OPs in control animals stayed the same or were slightly accelerated relative to their baseline values. For a given recording condition, OP kinetics were very stable over time and this stability was not disturbed in diabetic animals. Diabetic animals showed a small but significant delay in the a-wave, but no change in b-wave timing. The sensitivity of the b-wave was reduced twofold, but that of the a-wave was not changed. CONCLUSIONS: OPs have been used to evaluate retinal function in both diabetic models and patients. The comparison of amplitude-matched OPs is a robust determinant of changes in kinetics. Researchers and clinicians who use OPs may wish to consider the relationship between OP amplitude and kinetics to avoid confounding assessments of abnormalities. The amplitude versus kinetics relationship does not change form in diabetic animals; it is merely shifted (delayed) on the time axis.     

Contribution of N-methyl-dl-aspartic acid (NMDA)-sensitive neurons to generating oscillatory potentials in Royal College of Surgeons rats

Purpose

We investigated how the N-methyl-dl-aspartic acid (NMDA) receptor contributes to generating oscillatory potentials (OPs) of the electroretinogram (ERG) in the Royal College of Surgeons (RCS) rat.

Methods

Scotopic ERGs were recorded from dystrophic and wild-type congenic (WT) RCS rats (n = 20 of each) at 25, 30, 35, and 40 days of age. The stimulus intensity was increased from ?2.82 to 0.71 log cd-s/m² to obtain intensity-response function. NMDA was injected into the vitreous cavity of the right eyes. The left eyes were injected with saline as controls. The P3 obtained by a-wave fitting was digitally subtracted from the scotopic ERG to isolate the P2. For the OPs, the P2 was digitally filtered between 65 and 500 Hz. The amplitudes of OP1, OP2, OP3, and OP4 were then measured and summed and designated as ΣOPs. The implicit times of OP1, OP2, and OP3 were also measured. The frequency spectra of the OPs were analyzed using fast Fourier transform (FFT).

Results

The maximum ERG a- and b-waves as well as ΣOPs amplitudes reduced with age in dystrophic rats. Compared with intravitreal saline injection, administration of NMDA decreased ΣOPs amplitudes from 30 days of age in dystrophic rats, while it did not attenuate ΣOPs amplitudes in WT rats. The implicit times of the OPs of the maximum ERG were prolonged by NMDA injections in WT and dystrophic rats. NMDA/saline ratios of ΣOPs amplitudes area under the FFT curves were significantly lower in dystrophic rats from 30 days of age than that in WT rats.

Conclusion

In the early stage of photoreceptor degeneration, intravitreal NMDA injection attenuated OPs amplitudes in dystrophic rats. This indicates that NMDA receptors play a significant role in generating OPs amplitudes with advancing photoreceptor degeneration.     

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）