糖尿病视网膜病变与血脂,脂质过氧化的关系

目的:观察和探讨糖尿病视网膜病变与脂质代谢和脂质过氧化反应的关系。方法:对30名早期糖尿病视网膜病变患者与24名健康人空腹血清中甘油三脂(TC),总胆固醇(TG),高密度脂蛋白—胆固醇(HDL—C),低密度脂蛋白—胆固醇(LDL—C),过氧化物歧化酶SOD)和脂质过氧化物(LPO)的含量进行了检测。结果:发现患者组中TC、TG、LDL—C与LPO均明显高于对照组,而HDL—C与SOD都低于健康对照组。结论:糖尿病引起的脂质代谢紊乱和脂质过氧化反应的增强可能是促进视网病变的危险因素之一。眼科学报1998;14:100—102。     

视网膜光损伤及其药物防护的研究：脂质过氧化探讨

用荧光灯光源（１８１７５±３００ｌｘ）照射大鼠视网膜，经测定视网膜丙二醛（ＭＤＡ）含量判断视网膜脂质过氧化（ＬＰＯ）水平。结果发现：２小时光照３天后视网膜ＭＤＡ含量增高，５天后逐渐下降，８天后接近正常。分别用维生素Ｅ和β胡萝卜素抗损伤，表明两种药物均有抗光损伤ＬＰＯ作用，且与用药剂量、时间有关。     

小鼠视网膜紫外线光损伤中MDA与SOD的作用

目的:探讨视网膜紫外线光损伤中MDA与SOD的作用。方法:取健康成年昆明小鼠30只,随机分成正常对照组和实验组,实验组再分为光损伤后1,2,3,4wk组,每组6只,各组小鼠均在12h明(30～50Lux)12h暗环境中饲养7d,然后暗适应36h。正常对照组不予紫外线照射,实验组小鼠采用2200±138Lux波长为300～400nm的紫外线灯照射,每日连续光照8h。在模型制作完成后摘取眼球,左眼行视网膜匀浆中SOD活力与MDA含量测定。结果:紫外线光照组光照后SOD活力、MDA含量与正常对照组比较差别有统计学意义(P<0.05)。结论:慢性紫外线光损伤与脂质过氧化及自由基的产生有关。     

牛磺酸对离体视网膜组织脂质过氧化反应保护机制的实验研究

目的：探时牛磺酸对离体家免视网膜组织脂质过氧化反应、超氧化物歧化酶(superoxide dismutase,SOD)及谷胱过氧化物酶(glutathione，peroxidase,GSH-Px)活性的影响。 方法：将家兔眼球视杯置于4组(对照组、模型组、牛磷酸组、β—胡萝卜素组)培养液中，5%CO₂，37°C温育．分别于24小时和48小时时后测定视网膜组织中SOD，GSH-Px、蛋白及丙二醛(malondialdehyde，MDA)．结果：牛磺酸与β-胡萝卜索一样可以抑制视网膜组织内脂质过氧化反应，减少MDA生成；对SOD保护作用不确定，对GSH-Px无保护作用。 结论；牛磺酸可抑制视网膜组织脂质过氧化反应，其机制可能与对SOD,GSH—Px活性的膨响无关。 （中华眼底病杂志，1996，12：183-185）     

电光性眼炎与脂质过氧化反应间关系的实验研究

为了探讨电光性眼炎与脂质过氧化损伤之间的关系,本文对正常家兔和急性电光性眼炎家兔角膜上皮的超氧化物歧化酶(SOD)活性及脂质过氧化物主要降解产物丙二醛(MDA)含量进行测量。实验发现:正常兔角膜上皮内含有丰富的活性SOD和少量MDA。在紫外线照射后1/2小时至6小时,SOD含量均有降低,照射后3小时降达最低点(P<0.01)。伴随上述改变,角膜上皮内MDA含量增高,照射后3小时MDA含量达最高峰(P<0.001)。实验结果提示脂质过氧化损伤在急性电光性眼炎的发生。发展过程中起了重要作用。     

可见光对原代培养人视网膜色素上皮细胞的光化学损伤

目的：探讨视网膜光损伤的发生机制。 方法：利用2 400Lx白色荧光灯建立原代培养的健康成年人视网膜色素上皮(retinal pigment epithelium，RPE)细胞光化学损伤模型，进行透射电镜观察和超氧化物歧化酶(superoxidedismutase，SOD)检测。 结果：光照后线粒体肿胀，核膜结构模糊不清，部分损伤严重的细胞细胞器减少或消失，胞质空化，并见髓鞘样变性等改变；光照组细胞内SOD含量为对照组的41%（P＜0.05)。 结论：本实验条件下，光照使RPE结构损伤变性，细胞内SOD含量减少，提示与自由基产生和不能清除以及细胞内膜结构脂质过氧化反应有关。 （中华眼底病杂志，1996，12：174-175）     

实验性自身免疫性视网膜葡萄膜炎的视网膜脂类过氧化产物测定

目的探讨实验性自身免疫性视网膜葡萄膜炎（ｅｘｐｅｒｉｍｅｎｔａｌａｕｔｏｉｍｍｕｎｅｕｖｅｏｒｅｔｉｎｉｔｉｓ，ＥＡＵ）的组织损伤机理。方法利用视网膜Ｓ抗原诱发大鼠ＥＡＵ模型。在不同时间点，测定了视网膜脂类过氧化产物（共轭二烯、丙二醛、荧光色脂质及脂质氢过氧化物）的水平。结果在ＥＡＵ的病变过程中，脂类过氧化产物的水平均增高。结论自由基介导的脂类过氧化可能是造成ＥＡＵ视网膜病理损害的因素之一。     

老年性白内障超氧化物歧化酶脂质过氧化物的研究

测定22例老年性白内障患者血清内及房水内超氧化物歧化酶（SOD）和脂质过氧化物（LPO），结果老年性白内障患者血清及房水中SOD，活性较正常对照组明显下降，而LPO明显高于正常对照组。分析了SOD含量减少、LPO含量增多对老年性白内障的发生、发展的影响，认为老年性白内障形成与机体抗氧化能力下降有关，提出了提高机体SOD的含量在预防及治疗白内障中的作用。     

导光纤维引起兔视网膜光损伤的实验研究

目的：通过对导光纤维引起的兔眼视网膜光损伤。制造一种光损伤模型。为视网膜光损伤防治的研究提供一种有效的手段。方法：把405nm波长的单色滤光片，置于玻璃体切割机的光源处，使单色从导光纤维中导出，并用照度计测出光强度，将导光纤维插入兔眼内，根据光斑直径大小来决定导光纤维距照射部位的距离，以保证照射距离相等，所有兔的巩膜切口和照射部位均保持一致。选择一定的光能量照射兔眼，制成兔眼的视网膜光损伤模型。光照后3天。进行眼底检查并拍片，然后将兔处死。剪下照射部位，做光，电镜检查。结果：眼底镜检查可见光照射部位的视网膜水肿和脱色索，光，电镜检查可见光感受器细胞损伤的改变。在光镜下，随着能量的增加损伤程度也随之增加；在电镜下，因能量不同而引起的损伤程度的差别不明显。结论：导光纤维可以引起兔眼的视网膜光损伤，采用导光纤维制成的光损伤模型可进行有害波长的筛选。     

二硫化碳毒性视网膜损害的病理改变与脂质过氧化反应关 …

目的 探讨ＣＳ２毒性视网膜损害的病理学改变与脂质过氧化反应的关系。方法 对２０只家兔实验性二硫化碳中毒所致的视网膜损害作视网膜组织的光镜，电镜观察和脂质过氧化反应的生化检测。结果 视网膜超微结构：染毒兔视细胞变性，毛细血管内皮细胞囊样变。视网膜生化检测；８染毒兔视网膜丙二醛活性增高，超氧化歧化酶总活力降低。     

670 nm近红外光对大鼠视网膜光损伤的保护作用

目的 观察670 nm近红外光对SD大鼠的视网膜光损伤模型是否具有保护作用。方法 将32只SD大鼠分成8组,1组为正常对照组; 2组为红外光对照组; 3、5、7组为光损伤组;第4、6、8组为光损伤加近红外光保护组。光损伤剂量为900,1800,2700 lx白光,持续照射3 h;在光损伤前3 h和光损伤后0、24、48 h,保护组先后4次给予50 mW近红外光照射30 min。光损伤后第5天将大鼠置于暗室过夜,第6天作视网膜电图（ERG）检测,并取眼球作病理检查。结果 1组和2组视网膜细胞结构正常,外核层细胞约11层,ERG b波振幅（1088±55）μV。3组和4组900 lx白光持续照射3 h,未造成大鼠视网膜的损伤。5组1800 lx白光持续照射3 h,外核层细胞的减少至1～2层,内节（IS）与外节（OS）结构完全消失;损伤范围占全视网膜的0.48±0.12,损伤厚度占外核层全厚的L5=0.39±0.07,ERG的b波低伏（431±120 ）μV。6组在1800 Lux白光照射前后实施近红外光保护,视网膜损伤范围缩小为M6=0.17±0.12, （P5/6=0.002);损失厚度减少到L6=0.22±0.09 (P5/6<0.01）;ERG b波振幅升高到（1011±83）μV（P5/6<0.001）。2700 lx白光持续照射3 h,7组和8组病理和ERG检查的差异均无统计学意义［损伤面积:M7=0.83±0.09, M8=0.70±0.10, P7/8=0.074;损伤厚度L7=0.81±0.08, L8=0.73±0.08, P=0.17;ERG：H7=（234±26）μV,H8=（253±29）μV,P7/8>0.05］。结论 在一定的照射强度和时间范围内,670 nm近红外光对大鼠视网膜光损伤有明确的保护作用。     

LED光源对人视网膜色素上皮细胞分泌单核细胞趋化因子-1和白细胞介素-8的影响

目的　观察ＬＥＤ光源对人视网膜色素上皮（ｒｅｔｉｎａｌｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉａｌｃｅｌｌｓ,ＲＰＥ）细胞增生及分泌单核细胞趋化因子-１（ｍｏｎｏｃｙｔｅｃｈｅｍｏｔａｃｔｉｃｐｒｏｔｅｉｎ-１,ＭＣＰ-１）和白细胞介素-８（ｉｎｔｅｒｌｅｕｋｉｎ-８,ＩＬ-８）的影响。方法　传代培养的ＡＲＰＥ细胞分别置于５００ｌｕｘ、１０００ｌｕｘ的ＬＥＤ白光、蓝光、绿光中分别照射６ｈ、１２ｈ、２４ｈ,并分别设置对照组避光培养。采用ＭＴＴ法检测ＲＰＥ细胞的增生值（Ａ４６０）,分别使用Ｒｅａｌ-ｔｉｍｅＰＣＲ和ＥＬＩＳＡ法检测各组ＲＰＥ细胞ＭＣＰ-１和ＩＬ-８的表达水平。结果　ＭＴＴ法检测细胞增生值显示:蓝光、白光各组比较差异均有统计学意义（均为Ｐ＜０．０５）,白光５００ｌｕｘ２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,蓝光各照度６ｈ、１２ｈ、２４ｈ,ＲＰＥ细胞增生值均较对照组低,差异均有统计学意义（均为Ｐ＜０．０５）,细胞增生值随着白光和蓝光光照强度及光照时间的增加逐渐下降。ＲＴ-ＰＣＲ结果显示,各组ＲＰＥ细胞中ＭＣＰ-１和ＩＬ-８的ｍＲＮＡ比较差异均有统计学意义（均为Ｐ＜０．０５）。其中白光５００ｌｕｘ２４ｈ和１０００ｌｕｘ２４ｈ,蓝光５００ｌｕｘ１２ｈ、２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,绿光５００ｌｕｘ２４ｈ和１０００ｌｕｘ２４ｈ,各组ＲＰＥ细胞中ＭＣＰ-１和ＩＬ-８的ｍＲＮＡ表达水平较对照组高,差异均有统计学意义（均为Ｐ＜０．０５）。ＥＬＩＳＡ结果显示,白光５００ｌｕｘ２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,蓝光５００ｌｕｘ１２ｈ、２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,绿光５００ｌｕｘ２４ｈ、１０００ｌｕｘ２４ｈ,与对照组相比, ＲＰＥ细胞ＭＣＰ-１、ＩＬ-８分泌量增加,差异均有统计学意义（均为Ｐ＜０．０５）;蓝光在５００ｌｕｘ２４ｈ和１０００ｌｕｘ１２ｈ、２４ｈ,ＭＣＰ-１和ＩＬ-８分泌量较白光、绿光增加,差异均有统计学意义（均为Ｐ＜０．０５）。结论　ＬＥＤ白光、蓝光和绿光能以照度和时间依赖性影响ＡＲＰＥ细胞增生及分泌ＭＣＰ-１和ＩＬ-８,以蓝光更为显著。     

不同光谱组成的人工照明对视网膜色素上皮细胞的影响

目的 探讨不同光谱组成的人工照明对视网膜色素上皮(RPE)细胞的影响。方法 将体外培养的ARPE-19细胞随机分组：无光照对照组、非全光谱照明组(细分为300 lx、600 lx两个亚组)、全光谱照明组(细分为100 lx、300 lx、600 lx、900 lx四个亚组),无光照对照组细胞避光培养,其他组细胞采用相应光谱和光照强度干预。将分组光照24 h、48 h、72 h后的ARPE-19细胞置于倒置荧光显微镜下观察细胞形态变化;CCK-8法检测细胞活力;线粒体膜电位法检测线粒体功能。结果 光学显微镜下可见,光照72 h后,各组细胞密度明显增大,细胞大小不一,细胞多边形不典型;全光谱照明组细胞较非全光谱照明组细胞形态规整,异形细胞数少。光照24 h后,与无光照对照组相比,非全光谱照明300 lx组,全光谱照明300 lx、600 lx、900 lx组细胞活力均降低(均为P<0.05)。全光谱照明900 lx组细胞活力高于非全光谱照明300 lx组(P<0.05)。光照48 h后,各组细胞活力较光照24 h时提高;全光谱照明100 lx、300 lx组细胞活力低于非全光谱...     

Ultrastructural localization of light-induced lipid peroxides in the rat retina.

PURPOSE: Localization of light-induced lipid peroxides in the rat retina at an ultrastructural level as benzidine-reactive substances. METHODS: Long-Evans rats with nondilated pupils were exposed to intense light of 6000 lux for 12 or 24 hours. Control animals were kept under physiological light conditions. Rats with dilated pupils were exposed to a light intensity of 50 lux or 150,000 lux for 1 hour. For ultrastructural localization the enucleated eyes were fixed in a 0.1-M cacodylate buffer (pH 7.4) containing 2% glutaraldehyde for 2 hours. Pieces of the superior part of the central eyecup were incubated overnight with tetramethylbenzidine (TMB; pH 3.0) at 4 degrees C, postfixed with 1.5% OSO4, and embedded for electron microscopy. RESULTS: In animals exposed to intense light, electron-dense structures appeared exclusively throughout the rod outer segments after an irradiation of 6000 lux for 24 hours or 150,000 lux for 1 hour and were absent in animals with nondilated pupils kept at physiological light conditions. Dilation of the pupils leads to the appearance of electron-dense structures after just 1 hour of 50 lux, whereas rats with nondilated pupils withstand even a 12-hour irradiation with 6000 lux. No electron-dense structures were found when no TMB was used in incubation. CONCLUSIONS: The appearance of electron-dense structures in the rod outer segments depends on the incubation with TMB and intensive light exposure of the rat. Dilation of the pupils lowers the threshold for the emergence of electron-dense structures significantly. This strongly supports the view that light-induced lipid peroxides in the rat retina are localized at an ultrastructural level as benzidine-reactive substances. This protocol presents a tool for the generation and ultrastructural localization of lipid peroxides in rat retinas.     

The status of cones in the rhodopsin mutant P23H-3 retina: light-regulated damage and repair in parallel with rods

PURPOSE: This study tests whether cones in the rhodopsin-mutant transgenic P23H-3 retina are damaged by ambient light and whether subsequent light restriction allows repair of damaged cones. METHODS: P23H-3 rats were raised in scotopic cyclic (12 hours of 5 lux, 12 hours of dark) ambient light. At postnatal day 90 to 130, some were transferred to photopic conditions (12 hours of 300 lux, 12 hours of dark) for 1 week and then returned to scotopic conditions for up to 5 weeks. Photoreceptor function was assessed by the dark-adapted flash-evoked electroretinogram, using a two-flash paradigm to isolate the cone response. Outer-segment structure was demonstrated by immunohistochemistry for cone and rod opsins and by electron microscopy. RESULTS: Exposure for 1 week to photopic ambient light reduced the cone b-wave, the rod b-wave, and the rod a-wave by 40% to 60% and caused shortening and disorganization of cone and rod outer segments. Restoration of scotopic conditions for 2 to 5 weeks allowed partial recovery of the cone b-wave and the rod a- and b-waves, and regrowth of outer segments. CONCLUSIONS: Modest increases in ambient light cause rapid and significantly reversible loss of cone and rod function in the P23H-3 retina. The reduction and recovery of cone function are associated with shortening and regrowth of outer segments. Because the P23H mutation affects a protein expressed specifically in rods, this study emphasizes the close dependence of cones on rod function. It also demonstrates the capacity of cones and rods to repair their structure and regain function.     

老龄多巴色素异构酶敲除小鼠视网膜色素上皮细胞中黑色素在视网膜光损伤过程中的作用

目的 观察视网膜色素上皮(RPE)细胞中黑色素含量与光感受器细胞功能之间的关系,探讨黑色素对视网膜光损伤的作用.方法 老龄多巴色素异构酶敲除小鼠(Dct-/-小鼠)和C57BL/6小鼠(野生型小鼠)各20只,分别为Det-/-/小鼠组和野生型小鼠组.采用临床电生理国际标准分别对各型鼠进行视网膜电图(ERG)检查,记录其最大混合反应后各组随机处死2只小鼠,摘除眼球作为阴性对照.余下每组各18只小鼠,将6只小鼠用20 W冷荧光灯行12 h明、12 h暗、12 h明的间断光照36 h,连续3个循环.光照强度为(5000±356)lx.光照结束后第6天再次进行ERG检查,记录ERG结果.随机颈椎脱臼法处死每组各2只小鼠,摘除眼球.所有摘除眼球常规组织切片,光学显微镜、电子显微镜观察.结果 ERG检查结果显示,光损伤前后Dct-/-小鼠a、b波振幅明显低于野生型小鼠(t_(a波光照前)=-7.13,P＜0.01;t_(b波光照前)=-4.414,P＜0.01;t_(a波光照后)=-10.162,P＜0.01;t_(b波光照后)=-6.772,P＜0.01);光损伤后Dct-/-小鼠ERGa、b波的振幅下降幅度明显高于野生型小鼠(t_(a波)=4.975,P＜0.01;t_(b波)=2.908,P＜0.01).光损伤后,光学显微镜检查可见Dct-/-小鼠视网膜水肿、变薄,较野生型明显;电子显微镜检查可见RPE细胞中黑色素颗粒融解、断裂或丢失,光感受器细胞外节盘膜肿胀、碎裂及空泡变,Dct-/-小鼠损伤较野生型小鼠严重.结论 光损伤后RPE细胞黑色素含量减少,光感受器细胞功能下降,提示黑色素对光损伤可能有保护作用.     

Effect of light history on rod outer-segment membrane composition in the rat

Albino rats were born and raised through 12 weeks of age in 12L:12D regimes of 5, 300- or 800-lx illuminance. Upon killing, the animals' retinas were examined for the following: (1) rhodopsin of whole retina and isolated rod outer-segment membrane; (2) retinal morphology, including outer segment length and outer nuclear layer area; and (3) outer-segment membrane lipid biochemistry. The three groups of animals show significant differences with respect to one another for nearly every parameter measured. Rod outer-segment membranes of rats raised in dim cyclic light (5 lx) have high rhodopsin packing densities, high levels of polyunsaturated fatty acids, and low cholesterol levels in comparison with animals raised in brighter illuminances (300- or 800 lx). The mole ratio of phospholipid to rhodopsin in the outer-segment membrane of rats raised in 5-lx cyclic light is only 43% of that of rats raised in 800-lx cyclic light. The difference between these two groups of animals for docosahexaenoic acid is greater than three times, with dim light-reared animals showing higher levels. These rats (5 lx-reared) have less cholesterol in their photoreceptor outer segments, 6.6 mol% compared with 19.7 mol% for animals from the 800-lx regime. In all cases, rats from the intermediate rearing illuminance (300 lx) exhibit intermediate membrane composition values. It is likely that these differences in membrane composition illustrate a profound effect of light history on photoreceptor function.     

Cyclic light intensity threshold for retinal damage in albino rats raised under 6 lx

This study determined the minimum cyclic (12L:12D) light intensity which produces retinal damage in albino (Sprague-Dawley) rats raised from birth to 15 weeks of age under 6 lx (12L:12D). Four experimental light intensities were tested, viz. 1345, 270, 130 and 65 lx. Control animals remained under 6 lx. After various durations of exposure to one of the intensities tested, the retinas of groups of six rats were evaluated for physiological and morphological evidence of light damage. The indices of damage were: (1) histological and morphometric changes in the retina, and (2) changes in the amplitude and latency of the b-wave of the electroretinogram. Light intensities of 1345- or 270 lx severely damage retinas of albino rats raised from birth under 6 lx within 3-7 days of the initiation of light exposure. Exposure to 130- or 65 lx produced much less dramatic changes in the responsiveness and morphology of the retina that did not appear to be permanent. Based on these results, a reasonable estimate for the threshold cyclic-light intensity which produces damage to retinas of albino rats raised under 6 lx lies between 65- and 130 lx, or slightly more than 1 log unit above the light intensity under which the animals were raised. The effects of an animal's light history on retinal susceptibility to light damage are discussed.     

Reversal of functional loss in the P23H-3 rat retina by management of ambient light

The present experiments were undertaken to test recovery of function in the retina of the rhodopsin-mutant P23H-3 rat, in response to the management of ambient light. Observations were made in transgenic P23H-3 and non-degenerative Sprague-Dawley albino (SD) rats raised to young adulthood in scotopic cyclic light (12h 5 lx "daylight", 12h dark). The brightness of the day part of the cycle was increased to 300 lx (low end of daylight range) for 1 week, and then reduced to 5 lx for up to 5 weeks. Retinas were assessed for the rate of photoreceptor death (using the TUNEL technique), photoreceptor survival (thickness of the outer nuclear layer), and structure and function of surviving photoreceptors (outer segment (OS) length, electroretinogram (ERG)). Exposure of dim-raised rats to 300 lx for 1 week accelerated photoreceptor death, shortened the OSs of surviving photoreceptors, and reduced the ERG a-wave, more severely in the P23H-3 transgenics. Returning 300 lx-exposed animals to 5 lx conditions decelerated photoreceptor death and allowed regrowth of OSs and recovery of the a-wave. Recovery was substantial in both strains, OS length in the P23H-3 retina increasing from 17% to 90%, and a-wave amplitude from 33% to 45% of control values. Thinning of the ONL over the 6 week period studied was minimal. The P23H-3 retina thus shows significant recovery of function and outer segment structure in response to a reduction in ambient light. Restriction of ambient light may benefit comparable human forms of retinal degeneration in two ways, by reducing the rate of photoreceptor death and by inducing functional recovery in surviving photoreceptors.