大鼠半乳糖性白内障模型的表现和病理特征

背景建立稳定的糖尿病性白内障动物模型是研究白内障发病机制和药物治疗的前提。目前半乳糖性白内障模型已被广泛用于相关的研究,但不同的给糖方式会导致白内障出现的时间、程度及形态的差异。目的探讨半乳糖性白内障的眼部表现和病理特征。方法56只sD大鼠按随机数字表法随机分为模型组和对照组,每组28只。模型组大鼠用质量分数50％D－半乳糖饲料喂养SD大鼠共30d,对照组大鼠给予普通饲料喂养。喂养期间隔日在裂隙灯显微镜下观察晶状体的混浊部位及其形态,并对Suryanarayana提出的晶状体混浊的分级标准进行改良。于半乳糖喂养后的第5、10、15、20、25和30天分别观察大鼠的体质量变化,上述各时间点分别获取大鼠的晶状体并制作样本切片,行苏木精一伊红染色,检测晶状体的组织病理学改变。此外分别测量晶状体的湿质量和干质量,评估晶状体内水含量的变化特点。结果实验后10～30d,模型组大鼠的体质量较对照组均明显下降,差异均有统计学意义（P〈0．05）。在喂养半乳糖的过程中,随着时间的延长,模型组大鼠晶状体均发生不同级别的皮质和核的混浊,而对照组大鼠晶状体始终透明。裂隙灯下和晶状体的组织病理学检查均表明晶状体的混浊起始于赤道部皮质纤维,逐渐向中心区皮质扩展,随后晶状体核逐渐混浊、膨胀。组织学检查示晶状体皮质纤维水肿,晶状体上皮细胞分化、脱核延迟。实验第30天,模型组大鼠晶状体的湿质量明显高于对照组,差异有统计学意义（t=138．571,P〈O．05）;模型组大鼠晶状体的干质量明显低于对照组,差异有统计学意义（t=－52．468,P〈0．05）,实验过程中模型组大鼠晶状体干湿质量比明显下降,而对照组无明显变化,各时间点2组间的差异均有统计学意义（P〈0.05）。结论大鼠半乳糖性白内障模型的病程与人年龄相关性皮质性白内障的自然病程和发病机制相似。喂养50％D－半乳糖饲料造模的方法具有成模时间适中、临床分期特征明确等特点,是一种较理想的研究白内障发病机制和药物防治的模型。     

正常晶状体及年龄相关性白内障晶状体的超微结构观察

目的：探讨正常晶状体和年龄相关性白内障晶状体的超微结构变化。

方法：采用飞利浦208型透射电镜及日本产JSM-6380LV扫描电镜对3例正常的透明晶状体及5例行白内障囊外摘出的囊膜及晶状体核进行超微结构观察,并进行比较。

结果：透射电镜下白内障上皮细胞与正常组晶状体上皮细胞相比出现大量的异性核,染色质凝集,线粒体肿胀,减少,呈现空泡化; 白内障晶状体核区纤维细胞界限不明显,出现明显溶解、坏死改变。扫描电镜下白内障晶状体皮质纤维细胞失去光滑,晶状体核区纤维细胞表面因挤压而变形,细胞间的连接出现变化。

结论：白内障晶状体中上皮细胞及纤维细胞均发生了超微结构改变,这些变化可能是晶状体混浊的原因之一。     

醛糖还原酶抑制剂AL-1576对大鼠半乳糖性白内障的防治研究

背景 糖性白内障是糖尿病的主要眼部并发症之一,研究表明醛糖还原酶(AR)活性的升高与糖尿病的慢性并发症密切相关,是抗糖性白内障药物研究的重要靶点,其研究对糖性白内障的防治具有重要意义. 目的 探讨AR抑制剂AL-1576对半乳糖性白内障的防治效果和作用机制. 方法 4～5周龄SD大鼠42只,通过喂养质量分数50％半乳糖饲料制作半乳糖性白内障模型.大鼠按照随机数字表法平均分为7个组,AL-1576预防组,早、中、晚期治疗组在喂食50％半乳糖饲料的当天及5、10、15d后开始添加质量分数0.0125％ AL-1576,另设空白对照组、模型对照组和AL-1576干预10d后撤除的早期撤药组.在裂隙灯显微镜下动态观察各组大鼠晶状体的混浊程度并进行分级,造模35 d时摘出晶状体,分别测量其干质量、湿质量,计算并比较各组晶状体含水量的变化;检测造模35 d时各组大鼠晶状体内AR活性、超氧化物歧化酶(SOD)活性以及谷胱甘肽( GSH)的含量.结果 模型对照组大鼠12只眼晶状体均为Ⅳ级混浊,AL-1576预防组12只眼晶状体均透明,早期撤药组为Ⅱ～Ⅲ级混浊,早期治疗组为Ⅱ级混浊,而中期治疗组、晚期治疗组均为Ⅲ～Ⅳ级混浊,7个组晶状体混浊的程度差异均有统计学意义(H=17.760,P=0.009).各AL-1576治疗组大鼠晶状体含水量、AR活性均比模型对照组明显降低,差异均有统计学意义(P＜0.05),但给药的时间越晚,晶状体含水量、AR活性降低的程度越小;各AL-1576治疗组大鼠晶状体SOD活性和GSH的含量明显高于模型对照组,差异均有统计学意义( P＜0.05),AL-1576预防组的升高幅度最大. 结论 在半乳糖性白内障形成的不同阶段给予AR抑制剂AL-1576可明显抑制AR的活性.AL-1576通过阻断和减轻晶状体水肿,提高晶状体的抗氧化能力,预防和延缓晶状体混浊的发生.     

雌二醇对萘处理卵巢切除雌性大鼠晶状体形态结构的影响

目的:观察雌二醇对萘处理卵巢切除雌性大鼠晶状体细胞及组织形态结构的影响,探讨雌二醇对大鼠晶状体保护作用的形态学机制。方法:健康雌性、性成熟SD大鼠32只随机分为4组:卵巢切除组、卵巢切除+雌二醇组(雌二醇组)、卵巢切除+雌二醇和孕酮组(雌二醇+孕酮组)、正常对照组。术后2wk起各组均用300g/L萘混悬液灌胃(0.5g/Kgbw,2次/wk),肉眼和裂隙灯显微镜观察各组大鼠晶状体变化。灌胃6wk后处死大鼠,用放免法检测血清中雌二醇和孕酮浓度,取其晶状体分别进行光镜下组织细胞的形态观察,扫描电镜下晶状体纤维厚度及指突数的测定。结果:裂隙灯显微镜下,各组均有不同数量的大鼠晶状体出现空泡、小水裂以及前囊点状混浊,但各组间差异无显著性。光镜下,卵巢切除组表现出较其他三组更重的细胞和组织损害严重,而雌二醇组以及雌二醇+孕酮组则与正常组对照组表现相似。扫描电镜下,卵巢切除组晶状体纤维厚度较正常组增加(P<0.01),指突数较正常组少(P<0.01),而雌二醇组和雌二醇+孕酮组两项指标均与正常组接近。结论:雌二醇可能通过维持晶状体囊膜及晶状体上皮细胞正常结构,防止晶状体上皮细胞增殖,减轻晶状体皮质纤维细胞水肿,维持细胞连接的形态和数量,维持晶状体皮质纤维细胞的规则有序排列等途径发挥其对晶状体的保护作用。     

羟苯磺酸钙对大鼠半乳糖白内障抑制作用的研究

目的 观察不同剂量羟苯磺酸钙(CDO)对大鼠半乳糖性白内障的抑制和防治作用.方法 实验研究.选取20 d龄的两性Wistar大鼠50只按数字表法随机分为3组,空白对照组(10只)给予正常饮食喂养;模型对照组(10只)给予半乳糖溶液喂养(12.5％D-半乳糖喂养7d,后改为10％半乳糖喂养至实验结束);模型给药组分为高、中、低剂量组(各10只),半乳糖溶液喂养方法同模型对照组,同时分别采用灌胃针给以CDO低剂量75 mg·kg-1 ·d-1、中剂量150 mg·kg-1·d-1、高剂量300 mg·kg-1·d-1,灌胃至实验结束,共21 d.应用裂隙灯检查法观察各组大鼠晶状体的混浊程度;测定晶状体内抗氧化酶,即超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)和丙二醛(MDA)活性的变化;扫描电镜观察晶状体纤维超微结构的改变;HE染色观察晶状体上皮细胞组织形态学变化;TUNEL标记法观察晶状体上皮细胞的凋亡率.各组间比较采用单因素方差分析,两两比较采用Bonferroni检验,晶状体混浊程度及晶状体上皮细胞凋亡率采用秩和检验.结果 采用裂隙灯检查法观察模型给药组中晶状体混浊程度(Ⅲ级5只眼,Ⅳ级3只眼,Ⅴ级2只眼)低于模型对照组(Ⅳ级3只眼,Ⅴ级7只眼),但高于空白对照组(0级10只眼)(H=7.12,P＜0.05).给药组中的SOD及GSH-px活性高于模型对照组但低于空白对照组,第8天,空白对照组、模型对照组及高、中、低剂量给药组间SOD活性检测分别为(50.01±1.19)、(39.39±1.70)、(46.57±1.09)、(46.42±0.87)、(45.70±1.46) U/mg蛋白(F=88.70,P＜0.05);3个组间GSH-px活力检测分别为(42.92±0.97)、(12.70±1.17)、(29.16 ±1.05)、(29.08±0.98)、(28.25±0.98) nmol/mg蛋白(F=1071.89,P＜0.05);给药组中的MDA含量低于模型对照组但高于空白对照组,3个组间MDA含量测定分别为(2.57±0.13)、(3.43±0.15)、(2.89±0.11)、(2.99±0.12)、(2.99±0.09)nmoL/mg蛋白(F=64.62;P ＜0.05);且上述三项指标在给药组高、中、低剂量组间比较均无统计学意义(F=2.56,1.78,2.14;P＞0.05).扫描电镜观察,模型给药组晶状体纤维排列较模型对照组整齐但较空白对照组紊乱.HE染色光镜下观察空白对照组晶状体上皮细胞始终结构清晰、排列整齐;给药组及模型对照组晶状体上皮细胞均可由单层增殖为多层,纤维间层次排列逐渐紊乱.TUNEL标记模型给药组内细胞凋亡率明显高于空白对照组(0.23±0.07)％,但却低于模型对照组(4.99±0.51)％,3组凋亡率分别为(2.37±0.17)％、(2.46±0.26)％、(2.79±0.41)％(x2=40.41,P＜0.05).结论 不同剂量CDO均对半乳糖性白内障早期的发生发展有一定的延缓和预防作用,且不同剂量羟苯磺酸钙对半乳糖性白内障的抑制作用无明显差异.     

P38在体外培养鸡胚胎晶状体半乳糖性白内障形成中的作用

目的:探讨P38参与的晶状体上皮细胞凋亡的调节在体外培养的鸡胚胎晶状体半乳糖性白内障中的作用。方法:用30mmol/L半乳糖诱导体外培养的鸡胚胎晶状体建立半乳糖性白内障模型,在培养10d里,通过每日观察、照相、计算晶状体的混浊面积,观察MAPK-P38抑制剂SB203580对半乳糖引起的晶状体混浊程度的影响,并用TUNEL原位凋亡细胞染色方法,观察晶状体冰冻组织切片上细胞凋亡情况。结果:半乳糖30mmol/L能诱导体外培养的鸡胚胎晶状体产生周边皮质性混浊,随着半乳糖暴露时间的延长,晶状体的混浊面积增加,P38抑制剂SB203580能有效减轻半乳糖性晶状体的混浊。TUNEL检测显示,在培养2,5,10d的半乳糖性白内障晶状体切片上,凋亡细胞的百分数分别为1.7%,4.5%和12%,而SB203580处理的晶状体,凋亡细胞数明显减少,在相应点分别是0.7%,1.5%和1.4%。结论:P38可能通过参与晶状体上皮细胞凋亡调控在半乳糖性白内障的形成中起作用。抑制P38激活能阻止晶状体细胞凋亡,减轻白内障形成。     

半乳糖性白内障晶体上皮细胞游离钙的实验研究

目的研究半乳糖性白内障晶体上皮细胞中游离钙浓度变化规律。方法给２８天鼠龄的Ｗｉｓｔａｒ大白鼠投喂５０％的半乳糖饮食复制白内障模型后,分别于给药后第１,３,７,１０,１４及１９天测量晶体上皮细胞中游离钙的浓度。结果半乳糖性白内障各时期晶体上皮细胞中游离钙的浓度均明显升高,第１０天游离钙浓度最高,是正常对照组的４～５倍。结论半乳糖性白内障晶体上皮细胞中游离钙的浓度升高,各期上升的程度不同,以皮质混浊期升高幅度最大。     

牛磺酸对半乳糖性白内障大鼠房水和晶状体Ca2+含量及晶状体Ca2+-ATP酶活性的影响

目的探讨牛磺酸对半乳糖性白内障房水和晶状体中Ｃａ２＋含量及晶状体Ｃａ２＋－ＡＴＰ酶活性的影响。方法３３只２２ｄ龄Ｗｉｓｔａｒ大鼠随机分为正常对照组、白内障组和实验组；用Ｄ－半乳糖诱发半乳糖性白内障后，实验组在实验的ｄ４结膜下注射１５０ｇ·Ｌ－１牛磺酸；于实验的ｄ８、ｄ１４取房水和晶状体进行各项指标测定。结果白内障组与正常对照组相比，房水和晶状体中Ｃａ２＋含量明显升高，而晶状体Ｃａ２＋－ＡＴＰ酶活性下降；实验组与白内障组相比，房水和晶状体中Ｃａ２＋含量明显降低，而晶状体Ｃａ２＋－ＡＴＰ酶活性恢复至接近正常。结论牛磺酸能够抑制半乳糖性白内障发生过程中晶状体和房水Ｃａ２＋含量的增高并能提高晶状体囊膜Ｃａ２＋－ＡＴＰ酶活性。     

容积调控性氯通道与晶状体后囊膜混浊发病机制的关系

后囊膜混浊为白内障摘除术后残留在晶状体囊袋赤道部的晶状体上皮细胞异常增生移行至后囊膜并分化为成纤维细胞所致,其可直接影响患者术后视力及视觉质量.最近研究发现晶状体上皮细胞上表达多种类型的氯通道,其中容积调控性氯通道作为生物体内一类重要的阴离子通道,除了与细胞的容积调节有关,还在细胞增生、移行与分化等过程中起着重要作用,与晶状体后囊膜混浊形成相关.深入了解此通道可为术后晶状体后囊膜混浊的治疗和预防提供新的线索.     

阿霉素防治兔后囊混浊的实验与临床研究

目的研究阿霉素(adriamycine,ADR)对兔后发性白内障形成的影响及对兔眼的毒性作用.方法在12只兔眼晶状体囊外摘出术中分别注入0.2mLADR(0.4mg@L-1),然后观察术后不同时间角膜及晶状体后囊混浊变化,并结合观察术后病理学和电镜结构变化.结果12只兔眼注入ADR后1周炎性反应比对照组稍重,术后3～8周后囊膜明显比对照组清晰.组织病理学检查表明,对照组术后晶状体上皮细胞增生,而用药组明显抑制晶状体上皮细胞增生,且对角膜无明显毒性.ADR引起晶状体上皮细胞空泡变性、核固缩等,电镜观察发现用药组晶状体上皮细胞体积缩小、胞浆浓缩、染色质靠边聚集、包膜完整等典型的细胞凋亡形态.结论ADR能有效地抑制晶状体上皮细胞的增殖,预防兔后发性白内障的形成,且对兔眼毒性小,是-种有效的防治后发性白内障的药物.     

大鼠钝挫伤白内障模型的建立及其晶状体上皮细胞的超微结构观察

目的 建立钝挫伤白内障大鼠模型及探讨钝挫伤白内障与其晶状体上皮细胞凋亡的关系。方法 50只SD大鼠分成A、B、C、D、E共5组：分别用不同重量的小球，以不同次数连续从不同高度落下打击大鼠的左眼。裂隙灯下观察大鼠品状体的变化，用透射电镜观察晶状体上皮细胞凋亡的超微结构，并与自身对照眼比较。结果 实验开始1周后，5组实验眼的晶状体即出现不同程度的混浊，但是只有D组出现典型的、持续的环状混浊，其晶状体上皮细胞出现明显细胞凋亡的超微结构改变。各组自身对照眼晶状体上皮细胞超微结构无明显改变。结论 20cm高度20g重量的外力持续打击可以使大鼠较快产生典型的、持续的白内障。钝挫伤白内障的发生与晶状体上皮细胞凋亡有关。     

The Relationship between Osmotic Stress and Calcium Elevation: in vitro and in vivo Rat Lens Models

Bothin vivoandin vitromodels were employed in the present study to assess the relative contribution of osmotic stress and increasing calcium levels to the development of sugar cataracts. In galactose cataract obtained from galactosemic weanling rats, the concentration of total calcium increased by nearly 10% at the first sign of visible opacification observed on the fourth day post-galactose feeding. After 7 days of galactose feeding, calcium levels continued to rise, to 0.8 mm. During the first 10 days, loss of lens transparency and calcium elevation was gradual and steady, with precipitous changes occurring on days 11 and 12. In groups of rats where galactose feeding was stopped after 7 days, cataract reversal was followed during the next 5 weeks. During the initial first week of recovery, calcium influx and elevation in the lens continued but began to decline steadily thereafter. After 3 weeks of recovery, lens transparency had returned to almost normal. Calcium levels continued to decline and reached normal levels between day 34 and 42, nearly 4 weeks after removal of the galactose diet.The relationship between osmotic stress and calcium elevation was investigated more directly by culturing normal rat lenses in hypoosmotic medium (280 mOsm) to create osmotic gradients similar to that in galactosemic lenses. The results showed that during the first day of culture (12 hr), osmotically stressed lenses gained 3 mg of water, became opaque and gained excess calcium (7 mmcompared to 0.7 mm). Microscopic vacuoles appeared to accompany the process of opacification and contributed to increased light scattering and the loss of lens transparency.Additional experiments were designed to further distinguish between the effects of osmotic stress and calcium elevation on the opacification process. Thus, lenses were incubated in control and high-calcium medium (20 mm) at 300 mOsm. Within 12 hr of incubation, calcium elevation progressed to 1.37 mm, nearly doubling the normal value. Although opacification was observed in these lenses, no sign of vacuoles was evident. Collectively, the findings from this study support the premise that an early influx of calcium is brought about by osmotic stress and is responsible for the observed loss in transparency in osmotic (sugar) cataract.     

活体观察N-乙酰半胱氨酸防治白内障的实验研究

背景 亚硒酸钠诱导的白内障与年龄相关性白内障的形成机制具有一定的相似性,即氧化损伤,N-乙酰半胱氨酸(NAC)是一种有效的抗氧化剂,但其对白内障的预防和治疗作用研究尚少. 目的 观察NAC对亚硒酸钠诱导大鼠白内障的预防和治疗作用,为白内障的药物防治提供实验依据.方法 实验分为预防部分和治疗部分.选取SD大鼠60只,随机数字表法分为正常对照组1、正常对照组2、硒性白内障组、NAC白内障预防组、硒性白内障生理盐水组及NAC白内障治疗组,每组10只大鼠.采用3.46 mg/kg亚硒酸钠颈部皮下注射法制作硒性白内障模型,隔日1次,共3次.预防实验时在首次注射亚硒酸钠前30 min大鼠腹腔内注射2 mmol/L NAC,每日1次,共6次;治疗实验时,硒性白内障大鼠造模后1d腹腔内注射2 mmol/LNAC,每日1次,共1个月;硒性白内障生理盐水组以同样方法注射生理盐水.每周各组大鼠在裂隙灯下观察晶状体混浊程度并参考LOCSⅢ标准进行分级.各实验组大鼠最后一次注药后制备晶状体组织切片,光学显微镜下观察晶状体上皮细胞( LECs)的组织病理学改变,扫描电子显微镜下观察晶状体上皮超微结构的改变.采用免疫组织化学法观察亚硒酸钠对晶状体中caspase-3的影响;对各组大鼠晶状体组织中超氧化物歧化酶(SOD)、丙二醛(MDA)含量的变化进行生化测定.结果 实验后7d正常大鼠晶状体透明.硒性白内障组Ⅴ级晶状体混浊者有11只眼,NAC白内障预防组仅有Ⅱ级混浊8只眼和Ⅰ级混浊2只眼,差异有统计学意义(x2=40.000,P＜0.05).实验后30d,硒性白内障生理盐水组和NAC白内障治疗组Ⅳ～Ⅴ级晶状体混浊均为20只眼,差异无统计学意义(x2=0.153,P＞0.05).常规组织病理学检查表明,正常对照组LECs及晶状体纤维结构正常,硒性白内障组、硒性白内障生理盐水组和NAC白内障治疗组LECs与前囊部分分离,排列疏松紊乱,细胞膜破裂,细胞核呈椭圆形或长条形,晶状体纤维断裂,NAC白内障预防组晶状体结构破坏程度较轻.扫描电子显微镜下可见硒性白内障组、硒性白内障生理盐水组和NAC白内障治疗组晶状体前囊分层,外膜脱离,深层可见“变性球样小体”,纤维紊乱破碎,形成无结构的“水泥样”外观.硒性白内障组caspase-3和SOD的表达明显低于正常对照组,MDA的表达高于正常对照组,差异均有统计学意义(P＜0.05),而NAC白内障预防组caspase-3和SOD的表达明显高于硒性白内障组,差异均有统计学意义(P＜0.05).硒性白内障生理盐水组与NAC白内障治疗组caspase-3、SOD和MDA表达均明显低于正常对照组2,差异均有统计学意义(P＜0.05),而硒性白内障生理盐水组与NAC白内障治疗组比较,caspase-3、SOD和MDA表达的差异均无统计学意义(P＞0.05).结论 NAC可以提高晶状体组织中SOD的活性,减少MDA生成,降低caspase-3的活性,从而减轻晶状体的氧化损伤,对早期白内障的发生、发展有一定的延缓和预防作用,但对于已经形成的白内障无明显治疗作用.     

Effect of Pyruvate on Polyol Pathway and Lens Epithelial Cells Apoptosis in Diabetic Rats

A poptosis of lens epithelial cells (LECs) is considered as pathogenesis of several types of cataract formation[1]. Some studies have shown that apoptosis of lens epithelial cells plays an important role in the development of diabetic cataract[2]. Recently, it has been re- ported that apoptosis of lens epithelial cells isinduced when lens epithelial cells are cultured in mediumcontaininghigh glucose[3]. In the pre- sent study, rats were used to analyse apoptosis of lens epithelial cells in th…     

Crystallin synthesis and crystallin mRNAs in galactosemic rat lenses

Changes in crystallin synthesis and crystallin mRNA content were followed in the epithelial and fiber cells of rat lenses during the development and reversal of galactose cataracts. Crystallin synthesis was not lowered in the lens epithelial cells throughout the 18 days of galactose feeding. By contrast, crystallin synthesis appeared partially reduced in the fiber cells of cultured lenses after the rats had been on a diet of 50% galactose for 6 days, and was essentially arrested in the lens fiber cells after the rats were fed galactose chow for 12 or 18 days. In vitro translation tests in a rabbit reticulocyte lysate demonstrated that control lenses contained α-, β- and γ-crystallin mRNAs in the cortical and nuclear fiber cells. The lens fiber cells of the 6-day galactosemic rats still possessed a full complement of crystallin mRNAs but those of the 15-day galactosemic rats had no detectable crystallin mRNAs. After 12 days the galactosemic lenses had lost approximately half of the crystallin mRNAs from the cortical fiber cells and all of the mRNAs from the nuclear fiber cells. Both crystallin synthesis and crystallin mRNA content recovered in the cortical fiber cells, but not in the nuclear fiber cells, during reversal of the galactose cataract. These results indicate that the reduction in crystallin synthesis is confined to the fiber cells and occurs initially by a decreased efficiency of utilization of crystallin mRNAs and subsequently by the degradation of the mRNAs. Previous experiments provide evidence that the impaired utilization of the crystallin mRNAs is due to the alterations in electrolytes in the cataractous lenses.     

Incidence of posterior capsule opacification in eyes with and without posterior chamber intraocular lenses

The incidence of posterior capsule opacification after extracapsular cataract extraction was significantly lower in eyes implanted with posterior chamber intraocular lenses than in nonimplanted eyes. The number of loops fixated in the bag was significantly smaller in the eyes that became opacified than in those that did not. These findings suggest that the posterior chamber lens suppresses the two processes that lead to opacification: the development of a ring-shaped opacity at the site of contact between the anterior capsule rim and the posterior capsule and the migration of lens epithelial cells toward the center of the capsule. These suppressive effects were greater when the posterior chamber lens was fixated in the bag.     

猕猴白内障晶体上皮细胞超微结构研究

目的 探讨猕猴白内障晶体上皮细胞的超微结构,为将猕猴白内障作为人类白内障理想的动物模型提供病理学研究资料。方法 采用透射电镜对猕猴正常眼和猕猴白内障眼的晶体上皮细胞超微结构进行观察。结果 猕猴白内障眼晶体上皮细胞发生明显的变化：线粒体肿胀、空化、嵴消失,甚至形成凹空细胞;细胞水肿,细胞质溶解,甚至细胞崩解破坏;细胞核固缩、畸形,核膜间隙与核孙消失,核内异染色质浓集、周边化。结论 猕猴白内障上皮细胞     

Matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases in the human lens: implications for cortical cataract formation

PURPOSE: To characterize the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in human cortical cataract and to determine whether there is a correlation with the localization of cortical cataract. To evaluate the expression and activity of MMPs and TIMPs after cytokine and UV-B exposure in a human lens epithelial cell line. METHODS: Twenty-eight human donor eyes with cortical cataract and 21 normal human donor eyes were photographed. Thirteen cortical cataract and six normal lenses were immunohistochemically analyzed for MMP-1, -2, -3, and -9 and TIMP-1, -2, and -3. Twelve fresh cortical cataract and 12 normal lenses were divided into quadrants to quantify, by ELISA, the expression of MMP-1, -2, -3, and -9 and TIMP-1. Three fresh cortical cataract and three control lenses were assessed for MMP-1, -2, and -9 activity by SDS-PAGE zymography. Human lens epithelial cells (HLE-SRA-01/04) were exposed to proinflammatory cytokines and UV-B radiation to determine the protein expression profiles of MMP-1, -2, -3, and -9 and TIMP-1 and -2. RESULTS: Immunohistochemical analysis revealed specific localization of MMP-1 within lens epithelium and cortical lens fibers of cortical cataract. Normal lenses had equally low MMP-1, -2, -3, and -9 and TIMP-1, -2, and -3 immunoreactivity, expression, and activity in all lens quadrants. IL-1 and TNF-alpha upregulated the expression of MMP-2, -3, and -9, and UV-B upregulated the expression of MMP-1 in the SRA-01/04 HLE cell line. CONCLUSIONS: This is the first study to localize the expression of MMP-1 in cataracts with clinically observed opacification in vivo and to examine the expression induced by UV-B, in vitro.     

Biochemical changes in selenite cataract model measured by high-resolution MAS H NMR spectroscopy

PURPOSE: To correlate certain levels of lens opacification with high-resolution magic-angle spinning proton nuclear magnetic resonance (HR-MAS (1)H NMR) spectroscopy analysis of the biochemical changes in rat lenses in a selenite cataract model. METHODS: Selenite cataract was induced by injecting 13-day-old Sprague-Dawley rat pups with a single subcutaneous dose of sodium selenite (3.28 mg/kg in 0.9% sodium chloride solution). Lens opacification was observed using a photographic slit-lamp microscope at selected time-points 3, 6 and 9 days after selenite injection and was then graded (levels 0, 1 and 2). The animals were killed after the slit-lamp microscopy, lenses were removed and HR-MAS (1)H NMR spectra from intact lenses were obtained. Relative changes in metabolite concentrations were determined after comparison with matched lenses from untreated animals. RESULTS: Photographic slit-lamp microscopy revealed different stages of cataract in all animals treated with selenite. In the high quality HR-MAS (1)H NMR spectra of the lenses, more than 30 different metabolites were identified in each lens. With the exception of taurine, the concentrations of all amino acids showed a significant increase (p < 0.05) in the second level of cataract. By contrast, glutathione (GSH), succinate and phosphocholine concentrations were significantly reduced. CONCLUSIONS: For the first time, this study demonstrates the potential to correlate the level of lens opacification with the biochemical changes obtained with HR-MAS (1)H NMR spectroscopy analysis in a selenite cataract model.