糖尿病大鼠视网膜组织中Ca2+-Mg2+-ATPase活性变化的实验研究

目的:观察糖尿病大鼠视网膜组织中钙镁离子三磷酸腺苷酶(Ca2 -Mg2 -ATPase)活性的变化,探讨糖尿病视网膜病变发生发展的有关因素。方法:用孔雀绿比色分析法对糖尿病大鼠发病后不同时期视网膜组织中Ca2 -Mg2 -ATPase活性进行了检测,并与空腹血糖水平、糖基化血红蛋白含量、血脂、视网膜组织中Ca2 和Mg2 含量及糖尿病病程的关系进行了分析。结果:糖尿病大鼠视网膜组织中Ca2 -Mg2 -ATPase活性明显下降,Mg2 含量下降,Ca2 含量增高。Ca2 -Mg2 -ATPase活性与空腹血糖水平、糖基化血红蛋白含量、视网膜组织中Ca2 和Mg2 含量及糖尿病病程密切相关。结论:糖尿病大鼠视网膜组织中Ca2 -Mg2 -ATPase活性下降可能是其糖尿病视网膜病变的病理基础之一。     

镁对离体培养的视网膜组织cAMP的影响

将SD鼠视网膜分别培养在4种不同条件的Eagle培养液中。发现高糖正常镁（hGnMg）环境中视网膜组织环-磷酸腺苷（cAMP）含量最低。高糖高镁（hGhMg）液中，其cAMP含量明显回升，略高于正常对照组。而正常糖高镁（nGhMg）液中cAMP含量最高。提示糖尿病时视网膜组织中代谢紊乱。镁对维持和恢复其正常代谢有一定作用。（中华眼底病杂志，1992，8：138-140）     

晶体铜质异物眼内铜离子浓度与自由基代谢的实验研究

利用家兔晶体内铜异物动物模型测定不同时间角膜、房水、晶体、玻璃体铜离子浓度及丙二醛（ＭＤＡ）和超氧化物歧化酶（ＳＯＤ）含量。结果晶体内铜离子浓度和ＭＤＡ含量随病程进展呈上升趋势，ＳＯＤ活性逐渐下降，并导致异物周围晶体不同程度混浊；玻璃体在初期受到一定影响，１２天后恢复正常。表明晶格内铜异物可引起晶体内自由基代谢紊乱并导致晶体混浊，角膜、房水的自由基代谢亦有影响，对玻璃体影响不大。     

大鼠糖尿病早期给光/撤光中心视网膜神经节细胞分层的变化

目的探讨大鼠糖尿病早期给光／撤光中心视网膜神经节细胞（retinal ganglion cell，RGC）分层的变化规律，以解释糖尿病早期对比敏感度下降的原因。方法采用基因枪技术标记大鼠糖尿病早期RGC，以带Z轴的Leica显微镜和CCD照相机对标记的RGC进行拍照，并获得不同物像在纵轴的深度读数，分析树突层面在内丛状层的位置。结果①糖尿病第1个月和3个月时的撤光中心RGC的树突分层位置向内核层靠近，与正常大鼠相比差异有显著性（P〈0．001）。糖尿病第1个月和糖尿病第3个月时的给光中心RGC的树突分层位置与对照组相比差异均无显著性（P〉0．05）。②从分布上看，撤光中心RGC的树突分层向0％方向单向移动，这种变化主要出现在B类（糖尿病第1个月时P〈0．001，糖尿病第3个月时P〈0．01）和C类细胞（糖尿病第3个月时P〈0．001）中。给光中心RGC的树突分层比例与正常组相似，仅在糖尿病第1个月时A类细胞树突分层位置向内核层有所移位（P〈0．01）。③在糖尿病第1个月和第3个月时分别发现85个和119个的异常RGC细胞。结论糖尿病第1个月和第3个月时RGC细胞树突在内丛状层的分布受到了干扰，可能导致明暗刺激在视网膜上的不平衡，引起对比敏感度的下降。     

玻璃体内注射先锋霉素Ⅵ视网膜酶组织化学的实验研究

目的：研究先锋霉素Ⅵ玻璃体腔内注射的安全剂量。 方法：不同浓度的先锋霉素Ⅵ（100、200、250、300、400μg)注入不同组别的兔眼玻璃体腔内，以酶组织化学染色法确定注射后不同时间(1、3、7天)视网膜能量代谢酶琥珀酸脱氢酶(succinic dehydrogenase,SDH)和乳酸脱氢酶(lactic dehydrogenase,LDH)活性的变化并观察视网膜的组织结构及超微结构损害。 结果：随用药剂量增大，视网膜内SDH、LDH活性均逐渐降低；各剂址组活性分别于术后3天和术后1天降至最低，然后开始恢复，至术后7天100、200μg组恢复至正常，其余剂量组仍低于正常.100、200μg剂量组视网膜内仅出现水肿，而250、300、400μg组均出现细胞变性坏死、杆锥体脱失等改变。 结论：先锋霉索Ⅵ玻璃体腔内注射的安全剂量为200μg。 （中华眼底病杂志，1997，13：139-142）     

缺血再灌注大鼠视网膜细胞线粒体钙含量与组织型纤溶酶原激活物活性的相关性

目的观察缺血再灌注大鼠视网膜细胞线粒体钙含量与组织型纤溶酶原激活物（tissue-type plasminogena etivator，TPA）活性的变化，探讨两者之间的相关性。方法采用提高眼压法造成视网膜缺血后，恢复眼压形成血流再灌注。实验分正常对照组和缺血1h再灌注1h组、缺血1h再灌注2h组、缺血2h再灌注1h组、缺血2h再灌注2h组四个实验组，每组各取10例测定视网膜细胞线粒体钙浓度与TPA活性的变化，并进行相关性分析。结果缺血再灌注后，大鼠视网膜细胞线粒体钙含量与TPA活性随缺血和再灌注时间的延长而升高（P〈0．01），两者之间呈显著相关性（r=0．524，P〈0．01）。结论缺血再灌注可引起视网膜细胞线粒体钙含量的升高，从而导致视网膜组织TPA活性的增高，引起视网膜组织结构和功能的损伤。     

SOD和脂质过氧化反应在视网膜铜沉着症中的作用

测定了家兔眼球内铜异物伤后,视网膜中的抗氧化酶SOD活性和脂质过氧化反应产物MDA含量,以及玻璃体中铜离子浓度。SOD活性随玻璃体中铜离子浓度的升高而明显下降。7天时下降53.2%,4周时下降93.8%。MDA值在整个观察期间明显增高,最高达对照组的3倍,且与玻璃体中铜离子浓度的升高呈正相关。实验结果表明,脂质过氧化反应和视网膜SOD活性下降可能是眼铜质沉着症视网膜变性的重要因素之一。     

早期糖尿病大鼠视网膜谷氨酰胺合成酶的改变

目的 观察早期糖尿病大鼠视网膜谷氨酰胺合成酶（GS）的改变，探讨导致这种改变的发生机制。 方法 链脲佐菌素（STZ）诱导糖尿病大鼠模型，采用间接免疫荧光组织化学法和Western蛋白印迹法检测1、2、3个月糖尿病大鼠组和对照组大鼠视网膜GS、白细胞介素-1β（IL-1β）和即早基因（c-Jun）的表达变化。另外分别将0、100、500、1000 ng/ml IL-1β注入4组正常大鼠玻璃体腔中，24 h后采用同样方法检测视网膜GS和c-Jun表达的变化。 结果 对照组和1、2个月糖尿病大鼠组视网膜GS表达无明显改变，3个月糖尿病大鼠组GS表达与对照组相比明显下调（P<0.01）；对照组中IL-1β、c-Jun只有极低表达，糖尿病大鼠1至3个月时IL-1β、c-Jun表达逐渐升高，与对照组相比差异有统计学意义（P＜0.01）。玻璃体腔注射500、1000 ng/ml IL-1β可以使GS表达明显下调；注射100 ng/ml IL-1β就可以使c-Jun表达显著升高，并呈剂量依赖性。 结论 在早期糖尿病大鼠视网膜中，免疫相关因子IL-1β可使GS表达下降，其机制可能为IL-1β激活了c-Jun途径而影响GS的表达。 (中华眼底病杂志,2007,23:260-264)     

玻璃体腔磁性液体对兔视网膜组织病理变化的初步研究

目的探讨玻璃体腔注射不同浓度磁性液体后,兔眼视网膜组织病理学变化情况。方法将18只健康新西兰大白兔,双眼玻璃体腔注射不同浓度磁性液体,其中右眼注射浓度为1％,左眼注射浓度为0．5％。分别于注射后1d、1周、1个月和3个月采用裂隙灯显微镜活体观察兔眼前节形态,并于注射后1周、1个月和3个月分别处死6只实验兔,制备视网膜铺片,经苏木精-伊红染色后观察视网膜组织结构的变化。结果裂隙灯显微镜检查：术后1d,所有术眼前房清亮,未见明显Tyndall征;术后3个月,所有术眼也未出现白内障。视网膜切片可见,术后1周时磁性物质分布于视网膜前,术后1个月和3个月时磁性物质有所减少,整个过程均未见明显的视网膜及视盘组织结构的水肿。结论光学显微镜下两种浓度的磁性液体对兔视网膜组织无明显损伤。     

早期糖尿病大鼠视网膜形态变化及相关影响因子分析

背景糖尿病视网膜病变（DR）的病理基础是血-视网膜屏障受损,是多种因子共同影响的结果。目的探讨早期糖尿病大鼠视网膜形态变化与血清中血管内皮生长因子（VEGF）、内皮素（ET）和一氧化氮（NO）的关系。方法40只健康雌性SD大鼠按随机数字表法分为实验组和正常对照组,每组20只。实验组腹腔注射60mg／kg链脲佐菌素（STZ）建模成功后,按病程分为糖尿病2、4、6、8个月组;正常对照组腹腔注射等体积缓冲液,根据与实验组年龄匹配原则平均分为4组,每组5只。分别在造模后2、4、6、8个月采用ELISA双抗体夹心法测定2组大鼠血清中VEGF质量浓度,^125碘（^125I）放射免疫法测定血清中ET质量浓度,硝酸还原法测定血清中NO浓度并进行比较。于造模后8个月摘除大鼠眼球行常规视网膜组织形态学检查。结果正常对照组大鼠在实验各时间点视网膜组织形态学无明显改变。实验组大鼠造模后4个月开始出现视网膜组织水肿,视网膜各层细胞排列紊乱,造模后6个月可见视网膜出血,造模后8个月可见视网膜血管破裂。实验组大鼠在造模后2、4、6、8个月血清中VEGF和ET质量浓度较同时间点正常对照组大鼠明显升高,差异均有统计学意义（P〈0．05）,糖尿病2个月组血清中NO浓度较同时间点正常对照组升高（Z=-2．193,P〈0．05）,糖尿病4个月组与正常对照组比较,血清中NO浓度的差异无统计学意义（Z=-2．611,P〉0．05）,而糖尿病6个月组及糖尿病8个月组血清NO浓度较同时间点正常对照组低（Z=-2．449、-2．236,P〈0．05）。随着病程的延长,实验组血清中VEGF、ET质量浓度逐渐升高,NO浓度逐渐降低（P〈0．05）。糖尿病大鼠血清中VEGF与ET质量浓度间呈正相关（r=0．821,P〈0．01）,血清中VEGF质量浓度与NO浓度间呈负相关（r=-0．814,P〈0．01）;糖尿病大鼠血清中ET质量浓度与NO浓度间呈负相关（r=-0．803,P〈0．01）。结论糖尿病大鼠血清中VEGF、ET和NO水平与视网膜病理改变的严重程度密切相关,考虑血清中VEGF、ET与NO水平可以间接反映糖尿病大鼠视网膜病变的严重程度。     

Ontogeny of VEGF, IGF-I, and GH in neonatal rat serum, vitreous fluid, and retina from birth to weaning

PURPOSE: Vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF)-I, and growth hormone (GH) are major regulators of physical growth, as well as normal and pathologic retinal development. Ocular tissues are protected by the blood-ocular barrier. This study was conducted to test the hypothesis that the ontogenic profiles of VEGF, IGF-I, and GH in the rat serum, vitreous fluid, and retina are compartment specific, and that the vitreous is a reservoir for retinal growth factors. METHODS: Sprague-Dawley rat pups were killed at birth (postnatal day [P]0) and at P7, P14, and P21. At death, serum, vitreous fluid, and retinal homogenates were analyzed for ontogeny of VEGF, IGF-I, and GH. RESULTS: VEGF levels were 10 times higher in the vitreous than in serum at all stages of development. Vitreous and serum VEGF levels progressively declined, with lowest concentrations at P21. Retinal VEGF levels increased with the highest concentration at P21. IGF-I levels in the vitreous decreased from P7 through P21. IGF-I levels in serum and retinal homogenates increased with advancing postnatal age. Although IGF-I levels were four times higher in the vitreous than in the retina at P0, equilibration was achieved at P21. GH levels in the vitreous were 10 times lower than serum levels, were decreased at P14 and P21, and remained unchanged from P0 through P21 in the retina. CONCLUSIONS: VEGF and IGF-I act in concert to promote retinal development with the vitreous fluid as a reservoir. The ontogenic profiles of VEGF, IGF-I and GH in the serum and ocular compartments are specific. These differences should be considered when therapies for ROP are proposed.     

Phospholipid distributions and fatty acid composition of lysophosphatidylcholine and phosphatidylcholine in rabbit aqueous humor,lens and vitreous

The phospholipid distributions in rabbit lens and vitreous humor are remarkably similar to those of rabbit erythrocytes with a predominance of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) and lesser levels of sphingomyelin. A blood-aqueous and blood-vitreous barrier exists for phospholipids. In aqueous humor and vitreous humor, phospholipid concentrations were $\text{1}\text{2}$ to $\text{1}\text{30}$ those in serum. Only PE occurs in higher levels in vitreous than in serum, probably reflecting direct diffusion from the retina. Levels of lysophosphatidylcholine (LPC) in rabbit aqueous humor average 4·3 μg/ml. No LPC was present in rabbit lens. The fatty acid composition of PC and LPC was determined in lens, intraocular fluids, and serum. PC from rabbit ocular fluids or lens contains a higher proportion of saturated fatty acids than rabbit serum, and the long chain saturated fatty acids (>22:0) are found only in the ocular fluids.     

Clinical course, immune response, and histopathology of a simplified model of experimental lens induced endophthalmitis in rats

YAG laser capsulotomy 14 days after one-shot immunization of bovine lens soluble protein with Freund's complete adjuvant and simultaneous intravenous injection of Bordettella pertussis caused lens induced endophthalmitis (LIE) in Lewis rats. Exudate first appeared in the anterior chamber eight hours after capsulotomy. In the cases of low dose (20μg/rat) immunization, exudative change was localized around the ruptured lens surface. On the other hand, the anterior chamber was filled with thick exudate in high dose (200μg/rat) immunized rats. By ELISA and lymphocyte proliferation assay, serum and lymphocyte from LIE rats reacted with bovine uvea as well as bovine lens, but showed no cross-reactivity with bovine retina. Histopathological finding in the low-dose immunized rats was granulomatous inflammation localized to the anterior eye segment, but high dose-immunized rats developed severe panophthalmitis and showed epithelioid granulomas in disorganized retina. The authors think this low dose model can contribute to therapeutic or suppressive studies.     

羊毛甾醇合酶及羊毛甾醇在大鼠角膜、晶状体和视网膜组织中的分布

背景 已有研究证实与羊毛甾醇结构相似的三萜类化合物对于全身多种疾病具有治疗作用,近年来发现羊毛甾醇合酶(LSS)及羊毛甾醇对白内障具有治疗作用,但羊毛甾醇及其抑制剂与其他眼病的关系尚不清楚.了解羊毛甾醇在眼组织中的分布有助于阐明其与眼病的关系. 目的 研究正常大鼠角膜、晶状体和视网膜中LSS及羊毛甾醇的表达及分布,为相关眼科疾病的靶向治疗提供依据.方法 取SPF级雄性SD大鼠15只,采用戊巴比妥钠过量麻醉法处死实验大鼠,立即摘取眼球,分别采用Western blot和逆转录(RT)-PCR法检测大鼠角膜、晶状体和视网膜组织中LSS蛋白及其mRNA的表达情况;采用免疫荧光化学法对LSS在角膜、晶状体和视网膜组织中的表达进行定位;采用液相色谱-质谱联用仪(LC-MS)检测羊毛甾醇在正常大鼠角膜、晶状体和视网膜组织中的含量. 结果 Western blot法检测显示,大鼠视网膜中无LSS蛋白表达,LSS蛋白在晶状体组织的相对表达量为0.43±0.05,明显高于角膜组织中的0.25±0.03,差异有统计学意义(t =-5.35,P＜0.01).RT-PCR结果显示,正常大鼠视网膜中无LSS mRNA表达,大鼠角膜和晶状体组织中LSS mRNA的相对表达量为0.51±0.04,明显高于角膜组织中的0.29±0.02,差异有统计学意义(t=-8.34,P＜0.01).免疫荧光化学法结果表明,LSS主要表达于角膜上皮、基质和内皮层角膜细胞的细胞质以及晶状体上皮细胞和浅皮质层细胞,而视网膜组织中未检测到LSS表达,且视网膜中LSS与NeuN标记的神经元及谷氨酰胺合成酶(GS)标记的Müller细胞无共表达.LC-MS检测显示,正常大鼠视网膜中未检测到羊毛甾醇,大鼠晶状体中含羊毛甾醇为(24.37±2.91) ng/mg,明显高于角膜组织中的(5.31±0.58) ng/mg,差异有统计学意义(t=-11.13,P＜0.01).结论 LSS及羊毛甾醇分布于大鼠角膜各层组织以及晶状体组织中,在视网膜各层组织中均无LSS表达.     

INFLUENCE OF NEURAL RETINA ON LENS FIBRE DIFFERENTIATION IN RATS

Lens epithelial explants grown in retina-conditioned medium (RCM) undergo structural and molecular changes characteristic of fibre differentiation in the intact lens. We suggest that\n vivo neural retina releases a fibre differentiation factor (FDF) that interacts with equatorial lens epithelial cells and stimulates them to undergo fibre cell differentiation. According to this model, interaction with neural retina is essential for normal lens formation in embryos and for normal lens growth throughout life. Preliminary work on purification of the factor indicates that FDF activity is associated with a high molecular weight complex of 500 kd. The active component of this complex appears to be an 80 kd molecule.     

Oral flavonoids, chromocarb diethylamine salt and cyaninosides chloride, to eliminate lipoperoxidation postvitrectomy

This study was undertaken to determine the concentration of malondialdehyde, an end product of lipoperoxidation, in lens and retinal tissue postvitrectomy associated with oral administration of antioxidant flavonoids cyaninosides chloride and chromocarb diethylamine salt or N -acetylcysteine. Fifty adult pigmented rabbits were divided into five groups: (1) controls (normal eyes, malondialdehyde concentration in lens and retina); (2) vitrectomy with BSS Plus (malondialdehyde level measured 2hr after vitrectomy); (3) vitrectomy with BSS Plus and pretreatment with oral cyaninosides chloride 100mg kg day(-1)for 3 weeks (malondialdehyde level measured 2hr after surgery); (4) vitrectomy with BSS Plus and pretreatment with oral chromocarb diethylamine salt 100 mg kg day(-1)for 3 weeks (malondialdehyde level measured 2hr after surgery); and (5) vitrectomy with BSS Plus and pretreatment with oral N -acetylcysteine 200 mg kg day(-1)for 3 weeks (malondialdehyde level measured 2hr after surgery). Lens and retina samples were used to determine malondialdehyde levels using ion-pairing high performance liquid chromatography. Statistical analysis was done using analysis of variance (P<0.05). The content of malondialdehyde in the normal lens was 0.036 +/- 0.017 microg g(-1); in the vitrectomized groups the malondialdehyde concentrations were as follows: (2) 0.027 +/- 0.013 microg g(-1); (3) under detection limit (detection limit=1.75x e-3 microg g(-1)); (4) under detection limit; and (5) 0.020 +/- 0.006 microg g(-1). The results showed that the malondialdehyde concentration in the normal retina was 1.160 +/- 0.361 microg g(-1), while in the vitrectomized groups with or without pretreatment (cyaninosides chloride, chromocarb diethylamine salt, and N -acetylcysteine) the malondialdehyde levels were 2.091 +/- 0.982 microg g(-1), 0.069 +/- 0.024 microg g(-1), 0.082 +/- 0.027 microg g(-1), and 0.215 +/- 0.134 microg/g(-1), respectively, all significantly different from the normal eyes (P<0.05). Vitrectomy induced increased malondialdehyde levels in the retina. Oral flavonoids are an effective protective therapy for surgically induced lipoperoxidation, especially in the retina.     

Retinal changes in magnesium-deficient rats

The purpose of the present study is to investigate the retina in magnesium (Mg) deficiency and elucidate the local functions of trace elements. After delivery, mother Wistar Kyoto rats were fed a low Mg diet containing 0.1 mg Mg per 100 g diet with all other nutrients and distilled and deionized water. Infant rats were suckled by their mother rats for 21 days and then fed the same Mg-deficient diet. Control mother rats were fed commercial rat pellets containing 24 mg Mg per 100 g diet and all other nutrients. The retinas were examined by electron microscopy and secondary ion mass spectrometry (SIMS) microscopy at 6 weeks of age. In the Mg-deficient rats serum Mg levels were significantly lower and calcium (Ca) levels higher than in the control rats. The retinas of Mg-deficient rats showed multifocal necrosis in the pigment epithelial cells; photoreceptor cell outer segments were deformed near the necrotic cells, and some pigment epithelial cells contained many lamellar bodies. Many photoreceptor cell nuclei showed pyknotic (apoptosis-like) changes. SIMS images showed lower Mg concentration throughout the retina of the Mg-deficient rats, and the ratio of Ca to Mg concentration was significantly higher than in the control rats. Mg deficiency induces multifocal necrosis in the retinal pigment epithelial cells and pyknotic (apoptosis-like) changes in the photoreceptor cell nuclei. The changes in Mg-deficient retinas may be due to an imbalance in the distribution of Mg and Ca trace elements.     

Levels of zinc, iron, and copper in patients with pseudoexfoliative cataract

PURPOSE: To investigate the aqueous humor, lens, and serum concentrations of zinc, iron, and copper in patients with pseudoexfoliative cataract and compare with patients who have senile cataract without pseudoexfoliation. METHODS: Twenty-five patients with pseudoexfoliative cataract and 25 patients with senile cataract as control group were enrolled in the study. Samples from aqueous humor, serum, and lens materials during extracapsular cataract extraction (ECCE) were collected from all patients. The levels of selected trace elements in three samples in all groups were assayed with atomic absorption spectrometry (AAS) and statistical analyses were performed with t-test for independent samples except lens zinc and serum copper levels. The data weren't normally distributed, therefore Mann-Whitney U test applied for these parameters. RESULTS: The zinc and copper levels in aqueous humor of PEX group were significantly higher than those of control group (p<0.001). The iron levels in aqueous humor were not significantly different in PEX group and control group (p=0.252). The copper content of lenses was significantly increased in PEX group compared to control group (p=0.029). The iron and zinc content of lenses had no significant differences between the two groups (p=0.248, p=0.719, respectively). The levels of iron and copper in serum were significantly increased in PEX group compared to control group (p<0.001 and p<0.002, respectively). The zinc level in serum had no significant differences between the two groups (p=0.823, p=0.472, respectively). CONCLUSIONS: Zinc, iron, and especially copper may play a role in PEX syndrome.