Tetramethylpyrazine在视网膜色素上皮细胞变性及脉络膜血流和RPE细胞氧化应激中的作用

目的:研究1%Tetramethylpyrazine(TMP)在视网膜色素上皮细胞(RPE)变性,脉络膜血流和RPE细胞氧化应激中的作用。方法:在碘酸钠诱导的大鼠RPE变性研究中,1%TMP滴眼液预先处理1wk,3次/d,1wk后予碘酸钠舌下静脉注射,在2wk和4wk末,视网膜电图(ERG)测量c波。色素微球体技术分析高眼压状态下TMP对脉络膜血流的影响。Methylthiazoltetrazolium(MTT)分析TMP在各种氧化应激中对RPE的保护作用。结果:碘酸钠注射后2wk,碘酸钠组ERG的c波下降至对照组的36%(P<0.01)。4wk后,碘酸钠组下降至对照组的46%(P<0.01),而1%TMP+碘酸钠组下降至对照组的77%(P<0.01)。与碘酸钠组比较,1%TMP+碘酸钠组控制了67%的c波下降(P<0.05)。在脉络膜血流的测量中,30,60,和120min的结果显示,TMP显著增加脉络膜血流。在氧化应激部分,不同浓度的TMP在各种氧化应激损伤中,对RPE都有各种程度的保护作用。结论:浓度为1%Tetramethylpyrazine可以显著保护碘酸钠和氧化应激诱导的RPE变性,增加脉络膜血流,并可能在AMD的治疗中发挥作用。     

Tetramethylpyrazine在视网膜色素上皮细胞变性及脉络膜血流和RPE细胞氧化应激中的作用

目的：研究1% Tetramethylpyrazine （TMP）在视网膜色素上皮细胞（RPE）变性,脉络膜血流和RPE细胞氧化应激中的作用.方法：在碘酸钠诱导的大鼠RPE变性研究中,1%TMP滴眼液预先处理1wk,3次/d,1wk后予碘酸钠舌下静脉注射,在2wk和4wk末,视网膜电图（ERG）测量c波.色素微球体技术分析高眼压状态下TMP对脉络膜血流的影响.Methylthiazoltetrazolium （MTT）分析TMP在各种氧化应激中对RPE的保护作用.结果：碘酸钠注射后2wk,碘酸钠组ERG的c波下降至对照组的36%（P〈0.01）.4wk后,碘酸钠组下降至对照组的46%（P〈0.01）,而1% TMP ＋碘酸钠组下降至对照组的77%（P〈0.01）.与碘酸钠组比较,1%TMP ＋碘酸钠组控制了67%的c波下降（P〈0.05）.在脉络膜血流的测量中,30,60,和120min的结果显示,TMP显著增加脉络膜血流.在氧化应激部分,不同浓度的TMP在各种氧化应激损伤中,对RPE都有各种程度的保护作用.结论：浓度为1% Tetramethylpyrazine可以显著保护碘酸钠和氧化应激诱导的RPE变性,增加脉络膜血流,并可能在AMD的治疗中发挥作用.     

视网膜色素上皮细胞移植研究进展及存在的问题

近年来,视网膜色素上皮(RPE)细胞移植在治疗年龄相关性黄斑变性等疾病方面取得了一些进展。移植细胞根据来源和类型分为自体RPE细胞、自体虹膜色素上皮细胞、异体胎儿RPE细胞、异体成人RPE细胞、胚胎干细胞衍生的RPE细胞、诱导多能干细胞衍生的RPE细胞;根据移植方式分为RPE细胞悬液移植和RPE细胞片移植。自体RPE细...     

干性ARMD中视网膜色素上皮细胞的作用及损伤机制

年龄相关性黄斑变性(age-related macular degeneration,ARMD)是导致老年人中心视力不可逆丧失的主要原因。ARMD的典型特征是视网膜色素上皮(retinal pigment epithelium,RPE)和脉络膜毛细血管发生退行性改变及黄斑区出现玻璃膜疣。临床上ARMD分为两种亚型：非渗出型(干性或萎缩型)和渗出型(湿性或新生血管型)。该病的发生是年龄、环境、遗传、吸烟、氧化应激和心血管功能障碍等多种因素相互作用的结果。鉴于RPE细胞在ARMD发病中的重要作用,现以RPE细胞为重点,总结了蓝光、吸烟、氧化应激、脂褐素积累、慢性炎症和蛋白质稳态对干性ARMD发病的作用和可能机制,为认识和预防干性ARMD的发生提供新的帮助。     

H2O2对体外培养视网膜色素上皮细胞中BMP-6及其相关受体的影响

目的观察氧化应激对视网膜色素上皮(retinal pigment epithelium,RPE)细胞的损伤作用以及对骨形态发生蛋白(bone morphogenetic protein,BMP)-6及其相关受体的影响。方法 RPE细胞随机分为对照组:正常培养的RPE细胞;H₂O₂组:加入200μmol·L^-1H₂O₂处理的RPE细胞;实验组:加入200μmol·L^-1 H₂O₂和0.1 ng·L^-1 BMP-6的RPE细胞。采用活性氧(reactive oxygen species,ROS)检测试剂盒运用流式细胞仪检测对照组与H₂O₂组RPE细胞内ROS的变化,运用PCR及Western blot法检查对照组与H₂O₂组BMP-6基因及蛋白水平的变化;TUNEL染色法观察三组细胞凋亡的变化,并运用PCR及...     

干性年龄相关性黄斑变性患者视网膜色素上皮细胞损伤机制

年龄相关性黄斑变性(age-related macular degeneration,AMD)是中老年人视力障碍的重要原因之一。AMD分为2型:萎缩型(干性)和渗出型(湿性)。本文从光照损伤、脂褐素积累、氧化损伤、内质网应激4个方面,综述了干性AMD研究中基于视网膜色素上皮细胞损伤的相关研究进展,为进一步探索其发病机制提供依据和方向。     

视网膜色素上皮细胞移植的研究

视网膜色素上皮 (retinal pigm ent epithelium,RPE)由排列规则的单层细胞构成 ,位于视网膜神经上皮层和 Bruch膜之间 ,由于其特殊的解剖学位置 ,它在视网膜中起着重要的作用 [1 ]。 RPE、Bruch膜和脉络膜毛细血管的进行性病变可危及视网膜感光细胞 ,形成视网膜下的新生血管膜 ,比如老年黄斑变性 (age- related macular degeneration,ARMD)。传统的光凝疗法预后不佳 ,尤其在黄斑区 [2 ,3] 。近年来成功开展了视网膜下膜的“剥膜”手术 ,由于同时丧失了 RPE细胞 ,要求移植以作补充。由此带来了以下新课题 :(1) RPE的取材与培养 ;(2 )…     

艾塞那肽对4-羟基壬烯醛诱导人视网膜色素上皮细胞氧化应激损伤的抑制作用

目的观察艾塞那肽(exendin-4,EX4)对4-羟基壬烯醛(4-hydroxynonenal,4-HNE)诱导人视网膜色素上皮(retinal pigment epithelium,RPE)细胞氧化应激损伤的抑制作用。方法体外培养人RPE细胞(ARPE-19),采用CCK-8法检测不同浓度EX-4处理后细胞增殖情况;利用倒置显微镜观察对照组、EX4处理组、4-HNE组和4-HNE+EX4处理组细胞形态变化;利用荧光显微镜观察各组细胞的活性氧自由基(reactive oxygen species,ROS)生成;运用流式细胞仪检测各组RPE细胞内ROS含量变化;化学比色法检测细胞中超氧化物歧化酶(superoxide dismutase,SOD)和丙二醛(malondialdehyde,MDA)的含量变化。结果 100.0 nmol·L^-1 EX4对RPE细胞具有较强的保护作用,在此浓度下对10μmol·L^-1 4-HNE引起的氧化应激损伤具有较强的抑制作用(P<0.05)。荧光显微镜观察发现,与对照组相比,4-HNE组亮绿色高荧光信号...     

贝伐单抗对视网膜色素上皮细胞抗氧化功能的影响

目的 观察贝伐单抗对人视网膜色素上皮(retinal pigment epithelium,RPE)细胞抗氧化功能的影响,以探讨抗新生血管内皮生长因子(vascular endothelial growth factor,VEGF)制剂治疗年龄相关性黄斑变性后黄斑部萎缩的可能机制.方法 用含终浓度0.25g·L-1贝伐单抗的DMED/F12培养液培养人RPE细胞系ARPE-19细胞,根据处理时间的不同分为Oh组(对照组)、12 h组、24 h组、48 h组、72 h组共5组,加入H2O2诱导氧化应激反应.用CCK-8法检测细胞活性,MitoSox Red荧光染色检测细胞内线粒体活性氧(reactive oxygen species,ROS)产生水平,JC-1荧光染色检测细胞线粒体膜电位的变化;分别用逆转录聚合酶链反应(RT-PCR)及免疫蛋白印迹法(Western blot)检测各组促氧化因子NADPH氧化酶4(NADPH oxidase 4,NOX4)和抗氧化因子血红素氧合酶-1(heme oxygenase 1,HO-1) mRNA和蛋白的表达水平.结果 CCK-8检测结果显示:上述处理对细胞活性无显著影响,Oh组、12 h组、24h组、48h组和72 h组细胞活性分别为(100.2±3.3)％、(99.2±2.7)％、(102.5±6.4)％、(103.9±3.7)％和(103.6±3.3)％,差异无统计学意义(P＞0.05);与对照组相比,12 h、24h、48 h、72 h组细胞内ROS水平上升,差异有统计学意义(P＜0.05);线粒体膜电位在12 h、24h、48 h、72 h组均较对照组降低,差异有统计学意义(P＜0.01),48 h达最低,72 h时显著提高,但仍低于对照组.RT-PCR和Western blot检测结果显示:与对照组比较,NOX4 mRNA和蛋白的表达在12 h、24h、48 h和72 h组均上升,而且在24h表达最高,之后明显下降,但仍高于对照组,差异有统计学意义(P＜0.01).与对照组比较,HO-1 mRNA的表达在24h、48 h和72 h组均下降,而HO-1蛋白的表达在48 h和72 h组下降,差异有统计学意义(P＜0.05).结论 临床浓度的贝伐单抗可以降低RPE的抗氧化功能,可能是长期抗VEGF治疗后黄斑部进行性萎缩的原因之一.     

盐酸甲氯芬酯对人视网膜色素上皮细胞增生的影响

目的观察盐酸甲氯芬酯对体外培养的人视网膜色素上皮细胞增生的影响。方法通过MTT比色法和核仁嗜银蛋白染色分析,观察盐酸甲氯芬酯对人视网膜色素上皮细胞增生的影响。结果不同浓度盐酸甲氯芬酯可以促进人视网膜色素上皮细胞增生,在10~1000mg·L-1的范围内呈剂量效应关系,并随时间的延长,促进效应增强。嗜银蛋白染色结果:10mg·L-1盐酸甲氯芬酯作用24h后其胞核内AgNORs的数量增加,平均数为2.0(P=0.029);100mg·L-1盐酸甲氯芬酯作用12h即有胞核内AgNORs的增多,平均数为2.0(P=0.029)。随剂量的增加和时间的延长,胞核内AgNORs的数量增加。结论盐酸甲氯芬酯可以促进人视网膜色素上皮细胞增生,并与剂量和作用时间有一定的关系。     

青蒿素对过氧化氢诱导的人视网膜色素上皮（RPE）细胞氧化应激损伤的抑制作用

目的　探讨青蒿素对过氧化氢诱导的人视网膜色素上皮（retinal pigment epithelium,RPE)细胞氧化应激损伤的抑制作用。方法　将ARPE-19细胞接种于96孔板，每孔7×10³个细胞，细胞贴壁后分别加入不同浓度青蒿素，筛选对细胞增殖有效的最佳药物浓度。将APRE-19细胞分成4组。对照组:不做特殊处理；过氧化氢组:加入100 μmol·L^-1过氧化氢作用细胞24 h；青蒿素组:加入青蒿素30 μmol·L^-1，作用细胞24 h；青蒿素预保护组:加入30 μmol·L^-1青蒿素预保护细胞24 h后加入100 μmol·L^-1 过氧化氢作用24 h。利用MTT法筛选青蒿素对ARPE-19细胞作用的最佳药物浓度；通过Hoechst33342染色及线粒体膜电位观测细胞凋亡情况；检测细胞内超氧化物歧化酶（superoxide dismutase，SOD）含量和活性氧自由基（reactive oxygen species，ROS）阳性细胞数；Western blot法检测相关蛋白表达水平。结果　MTT法检测发现，30 μmol·L^-1的青蒿素对细胞增殖作用最强 （均为P<0.01）。青蒿素预保护组与过氧化氢组相比，细胞增殖率升高，凋亡细胞数显著减少，差异均有统计学意义（均为P<0.05）。线粒体膜电位染色显示，青蒿素预保护组与过氧化氢组相比绿色染色减少，红色染色增多，说明青蒿素预保护组凋亡细胞数减少。与对照组相比，青蒿素组ARPE-19细胞中SOD含量显著增加（P<0.05）；与过氧化氢组相比，青蒿素预保护组细胞内SOD含量明显增高（P<0.05），说明青蒿素能增加细胞内抗氧化物质，减少细胞凋亡。与对照组相比，青蒿素组ROS阳性细胞减少（P<0.05）；与过氧化氢组相比，青蒿素预保护组ROS阳性细胞亦明显减少（P<0.05），说明青蒿素可减少过氧化氢诱导的活性氧物质积聚。通过Western blot检测发现，青蒿素能促进ARPE-19细胞内AKT的磷酸化，过氧化氢组ARPE-19细胞内Caspase-3、PARP、 Keap1相对表达升高，Bcl-2、Nrf2、HO-1降低；青蒿素预保护组ARPE-19细胞内Caspase-3、PARP、 Keap1相对表达降低，Bcl-2、Nrf2、HO-1升高，差异均有统计学意义（均为P<0.05）。结论　青蒿素通过调节Nrf2/keap1信号通路来减小过氧化氢诱导的ARPE-19细胞的氧化应激损伤。     

Enhanced expression of glutathione-S-transferase A1-1 protects against oxidative stress in human retinal pigment epithelial cells

Glutathione-S-transferases (GSTs) play an important role in protection mechanisms against oxidative stress. We sought to determine whether over-expression of human GSTA1-1 in RPE cells is able to attenuate H(2)O(2)-induced oxidative stress. SV40-transformed human fetal RPE cells were stably transfected with pRC/hGSTA1-1 vector which carries a full-length of human GSTA1-1 cDNA. The control RPE cells were either non-transfected or transfected with control vector pRC. Expression of hGSTA1-1 protein in these cells was confirmed by Western blot and immunocytochemical analyses. The protective effects of hGSTA1-1 on cell viability and mitochondrial DNA (mtDNA) damage caused by H(2)O(2) were examined with MTT assay and quantitative PCR (QPCR), respectively. The hGSTA1-1 transfected RPE cells exhibited a similar morphology and growth rate as control RPE cells. Immunocytochemical analysis showed robust expression hGSTA1-1 in hGSTA1-1 transfected cells versus background staining in control cells. Western blotting of protein extracts from cells transfected with hGSTA1-1 revealed a 26 kDa protein band which corresponds to the size of recombinant mature hGSTA1-1. The active GST present in the hGSTA1-1 transfected cells was approximately three times higher than in control cells. The MTT assay showed a significantly greater viability of hGSTA1-1 cells in response to H(2)O(2) (100 and 200 microm) compared to control cells (p<0.05). QPCR indicated that mtDNA damage was significantly decreased in hGSTA1-1 cells than in control cells (p<0.05). Human GSTA1-1 transfection protect against RPE cell death and mtDNA damage caused by H(2)O(2), suggesting an important role of GST in protection against oxidative stress in RPE cells.     

内质网应激在氧化低密度脂蛋白诱导的人RPE细胞凋亡中的作用

目的：观察内质网应激(ERS)在氧化低密度脂蛋白(OxLDL)诱导的人视网膜色素上皮(RPE)细胞凋亡中的作用。

方法：人RPE细胞系ARPE19采用低糖DMEM培养基和10%胎牛血清进行常规培养。实验分为3组：对照组(常规培养的ARPE19)、OxLDL组(加入5、10、25、50、100μg/mL OxLDL)和LDL组(加入5、10、25、50、100μg/mL LDL)培养24h。分别采用细胞计数试剂盒(CCK8)检测各组细胞活性,流式细胞仪检测凋亡比例,蛋白质印迹(Western blotting)检测ERS相关蛋白及凋亡相关酶的表达。激光共聚焦显微镜观察人RPE细胞吞噬红色荧光探针Dil标记的氧化低密度脂蛋白(Dil-OxLDL)情况。

结果：CCK8结果显示：对照组细胞存活率为(100±5.637)%,加入5、10、25、50、100μg/mL OxLDL后细胞活力分别为(105.298±9.395)%、(97.106±5.417)%、(77.015±4.055)%、(67.613±3.853)%和(43.872±9.532)%(P<0.05); 加入5、10、25、50、100μg/mL LDL后细胞活力分别为(97.55±6.217)%、(99.640±3.586)%、(90.495±2.786)%、(83.552±9.171)%和(90.910±1.429)%(P>0.05)。流式细胞仪结果显示浓度为25μg/mL的OxLDL会明显诱导细胞凋亡,对照组、OxLDL组(25μg/mL)和LDL(25μg/mL)组凋亡率分别是(5.271±0.519)%、(41.23±1.686)%和(13.07±2.579)%(P<0.01); Western blotting结果显示OxLDL(25μg/mL)组的ERS相关蛋白和凋亡相关酶的表达量明显高于对照组与LDL组(Caspase-12：F=50.53, P<0.05; GRP78：F=55.60, P<0.05; CHOP：F=38.22, P<0.05; XBP-1：F=53.94, P<0.05; ATF6：F=20.01, P<0.05),而LDL组(25μg/mL)和对照组之间无差异(P>0.05)。

结论：ERS参与了OxLDL诱导的人RPE细胞凋亡,调控ERS可能抑制人RPE细胞凋亡,从而治疗RPE细胞凋亡相关疾病。     

Melatonin protects human retinal pigment epithelial (RPE) cells against oxidative stress

Oxidative stress is involved in the pathogenesis of age-related macular degeneration (AMD). Administration of conventional antioxidants has been shown to slow the progression of AMD and vision loss. Melatonin, an endogenous neurohormone produced by the pineal gland and retina, has been reported to be a potent antioxidant and free radical scavenger. In this study we tested whether melatonin can protect retinal pigment epithelial (RPE) cells against hydrogen peroxide (H(2)O(2))-induced cell death. Since mitochondrial DNA (mtDNA) is preferentially susceptible to oxidative damage, we tested whether melatonin can reduce H(2)O(2)-induced mtDNA lesions. A human RPE cell line (ARPE-19) was cultured and exposed to H(2)O(2) (100 and 200 microm) for 1 hr to induce cell death. Prior to H(2)O(2) treatment, cells were treated with various concentrations (0.1-200 microm) of melatonin for 2, 24 or 72 hr. Control cells received either melatonin or ethanol alone. Cell viability, as determined by MTT assay, showed no significant (P>0.05) protection against H(2)O(2) toxicity in cells receiving 2- and 24-hr pretreatment of melatonin at either concentration. However, when melatonin was administered diurnally for 3 consecutive days, this prolonged treatment markedly reduced H(2)O(2)-induced cell death (P>0.05) MtDNA damage, as assessed with quantitative PCR, was significantly decreased (P<0.05) in RPE cells pretreated with melatonin as compared to those without melatonin treatment. These results suggest that melatonin may play a role in protecting RPE cells from oxidative stress.     

Effects of flavone on the oxidation-induced injury of retinal pigment epithelium cells

AIM: To investigate the effect of flavone on oxidation- induced injury in retinal pigment epithelium cells. METHODS: In in vivo studies, NaIO3-induced RPE degene- ration in rat eyes was treated with 0.5% flavone eye drops 3 times a day for 1 week before and 4 weeks after NaIO3 injection. At the end of 2 and 4 weeks, all rats were measured c-wave by electroretinogram (ERG). In in vitro studies, ARPE-19 cells were treated with hypoxia, H2O2, NaN3 and t-BHP to induce cell damages. MTT assay was used to measure the viable cells. RESULTS: The ERG c-wave results showed that flavone reversed NaIO3-induced injury at the end of 4 weeks. In vitro results showed flavone reversed the various oxidants-induced injuries in RPE cells. CONCLUSION: Flavone could prevent the RPE from oxidation- induced injury both in vivo and in vitro.     

黄酮对视网膜色素上皮细胞氧化损伤的保护作用

目的:观察黄酮对氧化剂所诱导的视网膜色素上皮细胞(RPE)的保护作用。方法:在体研究中,预先给予5g/L黄酮滴眼液(3次/d),1wk后舌下静脉注射NaIO3诱导大鼠RPE变性,在2和4wk末,采用视网膜电图(ERG)测量C波。离体研究中,采用缺氧、H2O2、NaN3和t-BHP诱导RPE细胞损伤,并用MTT法检测细胞的存活率。结果:ERG的C波结果表明,第4wk末,黄酮抑制了由NaIO3诱导的大鼠RPE变性。离体研究结果表明,黄酮对多种氧化剂所诱导的RPE细胞损伤具有保护作用。结论:黄酮对氧化诱导的在体和离体视网膜色素上皮细胞均具有保护作用。     

Biological effects of native and oxidized low-density lipoproteins in cultured human retinal pigment epithelial cells

Age-related macular degeneration (AMD) and artherosclerosis share common characteristics in their pathogenesis. In this study, we investigated the effects of lipoproteins like native (n)-LDL, oxidized (ox)-LDL and high-density lipoprotein (HDL) on advanced senescence, extracellular matrix accumulation, cell loss, and transforming growth factor-beta2 (TGF-β2) expression in cultured human retinal pigment epithelial (RPE) cells. Primary human RPE cells were incubated with 10-100 μg/ml n-LDL, ox-LDL, and HDL for 24 h. For determination of advanced senescence, beta-galactosidase staining was used. The induction of fibronectin (Fn), laminin alpha 1 (Laa1), and collagen type IV alpha 2 (Col4a2) mRNA was quantified by real-time PCR. Cell loss was investigated by live dead assay. Expression of TGF-β2 was analyzed by real-time PCR and ELISA assays. Ox-LDL accelerated dose-dependently the onset of RPE senescence, whereas LDL and HDL had no effect. LDL and ox-LDL led to induced expression of Fn, Laa1 and Col4a2, whereas HDL had no influence. Incubation of RPE cells with 100 μg/ml ox-LDL induced marked cell death compared to untreated control cells. Expression of TGF-β2 was dose-dependently increased by LDL and ox-LDL.LDL and ox-LDL induced cellular changes in RPE cells in vitro, which may resemble pathogenic events of AMD. These results may provide further information about the effects of LDL and ox-LDL in the human RPE and their potential role in the pathogenesis of AMD.     

碘酸钠诱导非渗出型年龄相关性黄斑变性模型的研究

目的：研究10g/L胼酞嗪滴眼液对剂量为35mg/kg的NaIO3诱导的大鼠RPE变性的对抗作用。 方法：经舌下静脉予Brown Norway大鼠分别注射不同剂量的NaIO3及生理盐水,注射3,7,14及28d后测量ERG的a、b、c、FO及LP波,同时进行眼底彩照和眼底荧光血管造影检查。用光学显微镜或自体荧光平片对部分大鼠进行组织学研究。在体外培养RPE-19细胞,观察不同浓度的NaIO3对细胞的影响并测其细胞增殖率。经舌下静脉予BrownNorway大鼠注射剂量为35mg/kg的NaIO3。NaIO3组大鼠注射NaIO3后用生理盐水点眼,10g/L胼酞嗪＋NaIO3组大鼠注射NaIO3后用10g/L胼酞嗪滴眼液点眼,对照组不注射NaIO3,用生理盐水点眼,皆为3次/d,连续点4wk,然后测ERGc波。 结果：注射NaIO3后,高剂量组如30、40和60mg/kgNaIO3组的各种ERG波的振幅明显降低,低剂量组则变化不大。眼底彩照显示注射NaIO3后3d30mg/kg组出现部分视网膜坏死,视网膜坏死程度与注射后时间及注射量呈正相关,低剂量组没有明显改变。平片显示,注射NaIO3后3d30mg/kg组及更高剂量组单层RPE细胞出现坏死。组织学研究提示,注射NaIO330mg/kg组和低剂量组未发现明显变化。体外实验发现,浓度≥30mg/LNaIO3组RPE-19细胞增殖率降低。注射剂量为35mg/kgNaIO3后4wk,和对照组相比,NaIO3组大鼠ERGc波显著降低到对照组的31%（P〈0.01）。10g/L胼酞嗪＋NaIO3组和NaIO3组相比,大鼠ERGc波显著升高到对照组的50%（P〈0.05）。 结论：NaIO3诱导的PRE细胞凋亡受剂量和时间的双重影响。剂量为30-40mg/kgNaIO3适用于非渗出型年龄相关性黄斑变性的体内造模。胼酞嗪可能延缓非渗出型年龄相关性黄斑变性的发展进程,可能用于治疗非渗出型年龄相关性黄斑变性。     

Effects of hydralazine on NaIO3 -induced rat retinal pigment epithelium degeneration

AIM: To study the effects of 10g/L hydralazine eye drops on 35mg/kg NaIO₃ -induced degeneration in rat eyes. METHODS: Various doses of NaIO₃ and/or saline alone were injected into Brown Norway rats from hypoglossal vein. After 3, 7, 14 or 28 days of injection, ERG a-, b-, c-wave, fast oscillation (FO) and light peak (LP) were measured along with retinal colored pictures and fluorescein angiography(FA) taken. Some rats were chosen to study the histology of retinas by light microscopy and autofluorescence of retina flatmounts. Different concentrations of NaIO₃ were given to RPE-19 cells, and cell proliferation rate was measured. For hydralazine study, 35mg/kg NaIO₃ was injected into Brown Norway rat from hypoglossal vein. NaIO_{3 group was treated with saline alone after NaIO3 injection, 10g/L hydralazine+ NaIO3 group was treated with 10g/L hydralazine eyedrops after NaIO3 injection whereas normal group was treated with saline alone without NaIO3 injection. All eyedrops were instilled locally 3 times a day for 4 weeks and ERG c-wave was measured at the end of 2 and 4 weeks. RESULTS: After NaIO3 administration, the amplitude of all ERG waves fell markedly in large dose groups at 30, 40 or 60mg/kg NaIO3. Not many changes were observed in groups treated with <30mg/kg NaIO3. Some retinal necrosis appeared from 3 days post-injection (PI) in 30mg/kg NaIO3 group, which became more serious in larger dose groups or longer treatment time, but no apparent change was found in smaller dose groups. Similarly, on the retina flatmount, RPE monolayer showed necrosis from 3 days PI in the 30mg/kg NaIO3 and larger dose groups. On histological examination, no significant change was seen in 30mg/kg NaIO3 and lower concentration groups. In cell culture experiment, changes were found in RPE-19 cells proliferation rate with a concentration of NaIO3 at 30mg/L or higher. In hydralazine experiments, 4 weeks after injection of NaIO3, ERG c-wave fell markedly in NaIO3 group to 31% of control group(P <0.01). The ERG c-wave of hydralazine +NaIO3 group fell only to 50% of control group (P <0.05). This was a 61% reversal of the c-wave of NaIO3 treated group. CONCLUSION: Retinal pigment epithelium(RPE) degeneration induced by NaIO3 was both dose and time dependent. Around 30 to 40mg/kg NaIO3 would be the optimal to be used as a non-exudative age-related macular degeneration(AMD) rat model. Hydralazine may postpone the development of non-exudative AMD.}