热休克蛋白72在急性高眼压模型大鼠视网膜神经节细胞中的表达

目的检测热休克反应和硫酸锌腹腔内注射诱导热休克蛋白72(heat shock protein 72,HSP72)在急性高眼压模型大鼠视网膜神经节细胞(retinal ganglion cells,RGCs)中的表达及时间规律。方法以平衡盐溶液(barbitol buffer solu-tim,BSS)在前房内加压灌注制作大鼠急性高眼压模型;用热休克反应或硫酸锌腹腔内注射处理模型大鼠,在不同时间点处死大鼠,摘取模型眼,剥离视网膜,行Western blot分析。结果正常大鼠RGCs中无HSP72的表达。急性高眼压模型眼前房灌注BSS后6~36 h,RGCs内出现HSP72的微量表达,48 h后消失。热休克反应和硫酸锌腹腔内注射处理后,模型大鼠RGCs中均出现HSP72的表达,但HSP72的表达持续时间不同。热休克反应组,6 h出现HSP72的表达,以后逐渐增加,48 h达到最高峰,然后逐渐减弱,至反应后第8天消失;硫酸锌注射组,24 h后开始出现HSP72的表达,72 h达到最高峰,以后逐渐减弱,到第21天后消失。结论正常大鼠RGCs中无HSP72的表达;热休克反应和硫酸锌腹腔内注射均可以诱导急性高眼压模型大鼠RGCs中HSP72的表达。     

热休克蛋白72对大鼠急性高眼压性视网膜神经节细胞损伤的保护作用

目的探讨热休克蛋白72(heat shock proteiu,11SP 72)对大鼠急性高眼压性视网膜神经节细胞(1GCs)损伤的保护作用.方法右眼前房内灌注平衡盐溶液制作大鼠急性高眼压性RGC损伤模型;用热休克反应或腹腔内注射硫酸锌诱导模型大鼠RGCs中HSP 72表达,观察HSP72表达以后,模型大鼠RGC密度的改变情况,并与术处理的模型大鼠RGC密度相比较.结果正常大鼠RGC密度为2 504±181个/mm2;急性高眼压模型大鼠RGC密度为2 015±111个/mm2.热休克反应组和硫酸锌注射组RGC密度分别为2 207±200个/mm2和2 262±155个/mm2,显著高于模型组(P热休克=0.036,P硫酸锌=0.019);IISP 72阴性对照组与模型组RGC密度差异无显著意义(P槲皮黄酮 热休克=0.260,P槲皮黄酮 硫酸锌=0.748).结论热休克反应和腹腔内硫酸锌注射在急性高眼压模型大鼠RGCs中诱导产生的HSP72;可能对急性高眼压性RGC损伤具有保护作用.     

鼠青光眼模型中热休克蛋白27的表达及其作用

目的:探讨热休克蛋白27(HSP27)在鼠青光眼模型视网膜神经节细胞(RGCs)中的表达以及眼压对抗HSP27自身抗体的影响。方法:使用SPSS12.0软件将55只Wistar大鼠随机分为高眼压组(25只鼠)、sham对照(假手术)组(25只鼠)及正常对照组(5只鼠)。采用电凝鼠巩膜表面至少3组静脉及角膜缘周围血管,建立鼠青光眼模型。采用免疫组化和酶联免疫吸附测定(ELISA)方法分别检测术后1,2,3,4及8wk视网膜中RGCs以及神经纤维层(RNFL)HSP27的表达、分布以及血清中抗HSP27抗体水平。结果:随着眼压升高及高眼压持续时间延长,高眼压组右眼RGCs中HSP27表达逐渐增强,与其左眼、sham对照组右、左眼和正常对照组右、左眼比较,差异均有统计学意义(P<0.001),且RNFL中也出现HSP27的表达。高眼压组血清中抗HSP27抗体水平在术后1wk轻度升高(P>0.05),随着眼压升高及高眼压持续至术后8wk,血清中HSP27抗体水平逐渐升高并稳定于较高水平,与sham对照组和正常对照组比较,差异有统计学意义(P<0.05)。结论:内源性HSP27表达增强可能在青光眼视神经病变中具有重要作用。     

大鼠高眼压模型中热休克蛋白27抗体及视网膜神经节细胞凋亡的研究

背景 青光眼是一组以视网膜神经节细胞( RGCs)慢性丢失为特征的常见致盲性眼病.目前青光眼的发病机制尚不完全清楚,热休克蛋白27 (HSP27)抗体可能与青光眼视神经病变有关系. 目的 通过建立大鼠高眼压模型,检测血清中HSP27抗体的表达及RGCs的凋亡,了解HSP27抗体与眼压及RGCs凋亡的关系.方法 将51只Wistar大鼠按随机数字表法随机分为高眼压组34只和伪手术对照组17只,均取右眼为实验眼,左眼为对照眼.采用双极水下电凝器电凝高眼压组大鼠右眼巩膜表面3组静脉,建立高眼压动物模型.伪手术对照组大鼠右眼只剪开上方球结膜,不做电凝.分别于术后1、2、4、6、8周处死高眼压组大鼠6、6、6、8、8只,伪手术对照组大鼠3、3、3、4、4只.处死前测大鼠双眼眼压,并收集血清1 ml测定大鼠血清HSP27抗体.10只大鼠(2个组各时间点各1只)实验眼剥离视网膜,经匀浆后提取视网膜蛋白质用于Western blot分析.摘除剩余41只大鼠双侧眼球,制作石蜡切片.TUNEL法检测视网膜组织切片中RGCs的凋亡情况.结果 大鼠造模后3d,1、2、4、6、8周实验眼眼压较术前均明显增高,各时间点的总体比较差异有统计学意义( F=318.502,P＜0.01),但伪手术对照组手术前后眼压变化差异无统计学意义(F=2.076,P＞0.05).高眼压组大鼠实验眼视网膜HSP27蛋白水平与伪手术对照组大鼠实验眼比较均有升高.高眼压组大鼠术后1、2、4、6、8周血清中HSP27抗体各时间点总体比较差异有统计学意义(F=154.221,P＜0.01),随着造模时间的延长,血清HSP27抗体呈逐渐升高的趋势,而伪手术对照组手术前后HSP27抗体的变化差异无统计学意义( F=0.422,P＞0.05).高眼压组造模后实验眼不同时间点RGCs凋亡阳性细胞率比较差异有统计学意义(x2=856.12,P＜0.05).高眼压组不同时间点RGCs凋亡阳性细胞率均较伪手术对照组高(P＜0.05).结论 随着眼压的升高以及高眼压持续时间的延长,大鼠血清中的HSP27抗体水平逐渐升高,视网膜在高眼压状态下HSP27表达上调.逐渐升高的HSP27抗体水平与RGCs凋亡增加的趋势一致.     

腹腔注射银杏叶提取物促进大鼠视神经钳夹伤后视网膜神经节细胞存活

目的探讨银杏叶提取物GBE50（Ginkgo biloba extract 50）对大鼠视神经钳夹伤后视网膜神经节细胞（RGCs）的保护作用。方法65只SD大鼠随机等分为正常对照组、假手术组、模型组、模型＋生理盐水（NS）组、模型＋GBE 50组,每只鼠的右眼用于实验。正常对照组不作任何处理;假手术组仅分离暴露视神经;其余3个组分离暴露视神经并进行钳夹：模型＋NS组和模型＋GBE 50组分别于实验前1周每日腹腔注射相应体积NS和0．35％GBE 50（100mg／kg）,术后继续给药4周;术后4d,各组随机处死3只大鼠作凋亡RGCs的TUNEL荧光标记;术后4周后处死所有大鼠作光镜检查并计数视网膜垂直经线RGCs。结果正常对照组和假手术组未见TUNEL阳性RGCs;其余3组均见TUNEL阳性RGCs,但模型＋GBE 50组较前两组少。术后4周RGCs数目：模型组（131±10个）、模型＋NS组（137±13个）、模型＋GBE 50组（198±15个）均少于正常对照组和假手术组（P〈0．05）;模型组与模型＋NS组差异无统计学意义（P〉0．05）;但模型＋GBE 50组显著多于模型组和模型＋NS组（P〈0．05）。结论腹腔注射银杏叶提取物GBE 50能部分抑制大鼠视神经钳夹后RGCs凋亡,具有一定的RGCs保护作用。     

经瞳孔温热疗法对大鼠视神经钳夹视网膜神经节细胞的保护作用

目的探讨经瞳孔温热疗法（TTT）阈下反应对BN大鼠视神经钳夹后视网膜神经节细胞（RGCs）的保护作用。方法采用阈下TTT对BN大鼠视网膜进行照射后3d,通过逆行标记RGCs的方法,对TTT＋视神经钳夹组（A组）、TTT＋假手术组（B组）、单纯视神经钳夹组（C组）和空白对照组（D组）在视神经钳夹后1、2、4周进行RGCs计数并比较;检测视网膜TTT阈下反应的热休克蛋白70（HSP70）表达;观察TTT阈下反应对视网膜的影响。结果视神经钳夹后4周,A组RGCs数显著高于C组（P=0.006）,而1周和2周时2组之间差异无统计学意义（P〉0.05）;各时间点B组和D组的RGCs数差异无统计学意义（P〉0.05）。视网膜经阈下TTT干预后,HSP70表达高于对照眼。阈下TTT照射能引起视网膜组织形态上的改变。结论阈下TTT可显著提高视神经钳夹4周后RGCs的存活数量;其保护机制可能与诱导视网膜内源性HSP70表达、启动内源性保护机制有关。     

实验性大鼠青光眼模型诱导热休克蛋白27的表达

目的 测定热休克蛋白（HSP）家族中HSP27、HSP70和HSP90在正常和实验性大鼠青光眼模型视网膜中的蛋白质水平，探索其与青光眼视神经病变的潜在关系。设计 实验性研究。研究对象 60只Wistar大鼠。方法 将60只大鼠随机分为高眼压组（30只），假手术对照组（30只），右眼为实验眼，左眼为对照眼。采用双极电凝器电凝巩膜表面3组静脉，建立高眼压模型，用Tonopen眼压计检测眼压，每周2次，取眼压在27～35mmHg的大鼠进行研究。在眼压升高第10、20和60天处死大鼠，匀浆提取视网膜蛋白质用于Western印迹分析，并用β-actin校正点样误差。主要指标 眼压、Western印迹分析。结果 Western印迹分析显示。在眼压升高第10、20及60天，视网膜HSP27的蛋白质水平平均为对照组的197％。在实验眼视网膜内未观察到HSP70、HSP90蛋白质水平的变化。结论 在高眼压状态下大鼠视网膜HSP27上调，而HSP70和HSP90无变化。HSP27为眼压升高导致的特定基因改变，其持续过度表达可能与青光眼视神经病变有关。     

鼠青光眼模型视网膜神经节细胞中热休克蛋白27表达的研究

目的探讨热休克蛋白27(HSP27)在鼠青光眼模型视网膜神经节细胞(RGCs)中的表达及其与血清中相应抗体的关系。方法将49只Wistar大鼠随机分为高眼压组(32只鼠)、sham对照(假手术)组(12只鼠)及正常对照组(5只鼠)。电凝鼠巩膜表面至少3组静脉及角膜缘周围血管,减少房水静脉回流,建立鼠青光眼模型。分别于术后1、2、3、4及8周分别处死大鼠。处死前测眼压,抽血2ml,供酶联免疫吸附测定使用,分析视网膜组织内HSP27蛋白抗原产生的血清中相应抗体水平。同时对鼠眼视网膜组织进行石蜡切片,采用免疫组化法检测RGCsHSP27的表达及分布情况,并对检测结果进行统计学分析。结果高眼压组右眼术后眼压明显升高,术后3d眼压(27.52±6.63)mmHg(1mmHg=0.133kPa),术后1周眼压(31.42±6.18)mmHg,此后眼压基本稳定。术后各时间点高眼压组右眼眼压与其术前、左眼及sham组右眼和左眼比较,差异有统计学意义(P<0.01)。血清中抗HSP27抗体滴度在术后1周缓慢升高,2、3周达高峰,此后逐渐下降至接近正常水平。术后2周和3周,高眼压组血清中HSP27抗体含量与sham对照组和正常对照组比较,差异有统计学意义(P<0.01和P<0.05)。RGCs中HSP27阳性表达率在术后各时间点,高眼压组右眼与左眼、sham对照组右眼和左眼及正常对照组右眼和左眼比较,差异有统计学意义(P<0.01)。RGCs中HSP27阳性表达随着眼压升高及高眼压持续时间延长逐渐增强,且视网膜神经纤维层中也出现较明显的HSP27的阳性表达。结论内源性HSP27表达增强可能在青光眼视神经病变中具有重要作用。     

表没食子儿茶素没食子酸酯对大鼠视神经钳夹伤后胶质纤维酸性蛋白表达的影响

背景先前的研究已证实,绿茶提取物表没食子儿茶素没食子酸酯（EGCG）能提高大鼠视神经钳夹伤后视网膜神经节细胞（RGCs）的生存率。星形胶质细胞（AS）在神经系统损伤中对神经元的修复起重要作用,而EGCG对视神经钳夹伤后AS反应活性的影响尚有待证实。胶质纤维酸性蛋白（GFAP）是AS的特异性标记物。目的观察EGCG对大鼠视神经钳夹伤后视神经GFAP表达的影响。方法将72只Wistar大鼠随机分为正常对照组、假手术＋EGCG组、视神经钳夹伤＋生理盐水组、视神经钳夹伤＋EGCG组,每组18只。于大鼠球后2mm处用夹持力dOg的微型视神经夹垂直视神经钳夹60s建立视神经钳夹伤模型,似手术大鼠仅切开眼外软组织,不损伤视神经。假手术＋EGCG组和视神经钳夹伤＋EGCG组大鼠术前2d起每日给予25mg／kgEGCG腹腔注射至术后2d,随后改为每日2mg／kg口服。采用免疫组织化学染色及Westernblot法检测并比较各组大鼠造模后7、1d、28d视神经组织中GFAP的表达。结果免疫组织化学染色显示,正常对照组和假手术＋EGCG组视神经组织中GFAP呈弱表达;造模后7、14、28d,视神经钳夹伤＋生理盐水组GFAP表达明显增强,视神经钳夹伤＋EGCG组GFAP的表达强于正常对照组,弱于视神经钳夹伤＋生理盐水组。Westernblot检测表明,造模后视神经组织GFAP的表达量较正常对照组明显增高,差异有统计学意义（P〈0．01）;造模后7d、14d,视神经钳夹伤＋EGCG组GFAP的表达量明显低于视神经钳夹伤＋生理盐水组,差异均有统计学意义（P〈0．05）。结论全身应用EGCG可以下调大鼠视神经钳夹伤后视神经组织中GFAP的表达,降低AS的增生活性,提示EGCG可以抑制视神经创伤修复过程中的瘢痕形成。     

兔视神经损伤后视网膜一氧化氮的表达与神经节细胞凋亡关系的研究

目的通过建立兔视神经夹伤模型,观察伤后视网膜组织中一氧化氮的表达与视网膜神经节细胞（RGCs）凋亡的关系,从而探讨RGCs凋亡机制及氨基胍（AG）在伤后对RGCs的保护性作用。方法55只成年大耳白兔,随机分正常对照组（5只）、损伤对照组（25只）、AG治疗组（25只）。损伤组双眼夹伤视神经,按伤后1、3、7、14、21d又随机分为5组（5只／组）。AG治疗组于伤后2min耳缘静脉注射2％AG,损伤对照组同法注射生理盐水。应用TUNEL染色计数凋亡阳性细胞;比色法测量一氧化氮（NO）含量、诱导型一氧化氮合酶（iNOS）活力。结果正常组视网膜切片中极少见RGCs凋亡。损伤组于伤后1d偶见,3—7d逐渐增多,至14d达高峰,之后逐渐下降。正常视网膜组织中很少表达iNOS,但含有少量NO。在损伤后二者含量逐渐增高,与RGCs凋亡呈正相关性。同一时间点损伤对照组和AG治疗组比较差异有统计学意义。结论兔视神经夹伤后,NO合成增多可能是引起RGCs凋亡的一个因素。而AG通过减少NO的合成,降低RGCs凋亡,对RGCs有保护性作用。     

Induction of Heat Shock Protein 72 in RGCs of Rat Acute Glaucoma Model after Heat Stress or Zinc Administration

Purpose:To investigate the dynamics of heat shock protein 72 (HSP72) expression in retinal ganglion cells (RGCs) in rat model of acute glaucoma treated with heat stress or intraperitoneal injection of zinc sulfate.Methods : Twenty-seven male Wistar rats were used to make acute glaucoma models. Five others served as normal control. Acute glaucoma models were made by intracameral irrigation in the right eyes with balanced salt saline (BSS) at 102 mmHg for 2 hours. Nine model rats were killed at different intervals after intracameral irrigation without treatment, which served as damage control. Ten were treated with heat stress 40℃-42℃, and 8 were used for zinc sulfate administration 2 days posterior to intracameral irrigation.Treated model rats were sacrificed at designed intervals after treatment. Right eyes were enucleated immediately, and the retinas were dissected for Western blot.Results : No HSP72 was found in RGCs of normal Wistar rats. In damage control group,slight HSP72 was detected during 6-36 hours posterior to intracameral irrigation. HSP72 was detected significantly expressed in RGCs of both heat shock group and zinc sulfate group. But the dynamics of HSP72 production were quite different in these two treated groups. In heat shock group, HSP72 appeared at the sixth hour after treatment, and increased gradually until its peak production emerged at the 48th hour. HSP72 vanished 8 days later after treatment. In zinc sulfate group, HSP72 expression began 24 hours later after zinc administration, and reached its highest level at the 72th hour posterior to treatment. HSP72 expression then decreased slowly, and disappeared 21 days later aftertreatment.Conclusion:HSP72 can be induced in RGCs of rat acute glaucoma models with heat stress or zinc sulfate adddministration. But the dynamics of the HSP72 induction in those two groups were quite different.     

Induction of heat shock protein 72 protects retinal ganglion cells in a rat glaucoma model

PURPOSE: To investigate whether heat shock protein (Hsp) 72 is induced in retinal ganglion cells (RGCs) in experimental rat glaucoma and whether the induction of Hsp72 by heat stress or zinc (Zn(2+)) administration can increase survival of RGCs in the model. METHODS: Intraocular pressure (IOP) was elevated unilaterally in Wistar rats with argon laser irradiation of the trabecular meshwork 5 days after intracameral injection of india ink. Immunohistochemical staining for Hsp72 was performed. The rats with elevated IOP were treated with heat stress once a week (six rats) or intraperitoneal injection of zinc (10 mg/kg) every two weeks (six rats). Untreated rats with elevated IOP served as a control group (six rats). Quercetin, an inhibitor of Hsp expression was injected in the rats with heat stress (six rats) and zinc injection (seven rats). Subsequent to 4 weeks of IOP elevation, RGCs were counted. RESULTS: The IOP increase compared with the contralateral eyes was 48% +/- 4% throughout the study period. Hsp72 was detected only in the eyes with elevated IOP at 1 and 2 days and was weakly detected at 1 week of IOP elevation. A single administration of zinc strongly induced Hsp72 in RGCs of rats with elevated IOP for 2 weeks. Treatment with heat stress or zinc in rats with elevated IOP increased RGC survival after 4 weeks of IOP elevation, compared with the untreated control group (P = 0.004, n = 6). Quercetin reversed the positive effect of heat stress or zinc injection on RGC survival. CONCLUSIONS: These results demonstrate the possibility of a novel therapeutic approach to glaucoma through an enhanced induction of the endogenous heat shock response.     

Heat Shock Protein 72 Protects Retinal Ganglion Cells in Rat Model of Acute Glaucoma

Purpose: To investigate whether the induction of heat shock protein (HSP)72 by heat stress (HS) or zinc (Zn2 ) administration can increase survival of retinal ganglion cells (RGC)in rat model of acute experimental glaucoma. Methods: Acute glaucoma model was made by intracameral irrigation with BSS at 102 mmHg for two hours in right eyes of male Wistar rats. Glaucoma model rats were treated with HS once a week (six rats) or intraperitoneal injection of zinc sulfate (24.6 mg/kg) every two weeks (six rats), and were referred to as HS group and zinc group, respectively. Untreated model rats served as damage group (six rats). In control groups, querc-etin (400 mg/kg) was intraperitoneally injected to inhibit the induction of heat shock proteins 6 hours before HS or zinc administration, and were referred to as HS que group (six rats) and zinc que group (six rats), respectively. Subsequent to 16 days of IOP elevation, the rats were sacrificed. Eyes were quickly enucleated, and the retinas were dissected. RGC were labeled with Nissl staining and counted under microscope. Results: The average RGC density in normal Wistar rats was (2504±181) cells/mm2. In damage group, it decreased to (2015±111) cells/mm2. The RGC densities at 1,2, and 3 mm from the center of the optic nerve head were (2716±215), (2496±168), and (2317±171) cells/mm2, respectively, for normal rats and (2211±133), (1969±154), and (1872±68) cells/mm2, respectively, for damage group. The latter was significantly lower at all locations compared with the former (P=0.027 for each, Mann-Whitney test). The average RGC densities were (2207±200) cells/mm2 for HS group, (2272±155) cells/mm2 for zinc group, (1964±188) cells/mm2 for HS que group, (2051 ±214) cells/mm2 for zinc que group and (2015±111) cells/mm2for damage group. There were significant differences in density of labeled RGCs among the five groups (P=0.040, Kruskal-Wallis test). Both HS and zinc group had higher RGC densities than damage group (P =0.036 between HS and damage group,P=0.019 between zinc and damage group,Mann-Whitney test). There was no significant difference in RGC densitiy between control groups and damage group (P=0.260 between HS que and damage group,P=0.748 between zinc que and damage group, Mann-Whitney test). Conclusions: The results demonstrated that the induction of HSP72 in RGCs by HS or zinc administration plays an important role in the survival of RGCs in rat model of acute glaucoma. A novel therapeutic approach to glaucoma through an enhanced induction of endogenous HSP72 could be possible. Eye Science 2005;21:163-168.     

Retinal ganglion cell protection with geranylgeranylacetone,a heat shock protein inducer,in a rat glaucoma model

PURPOSE: To study the effects of geranylgeranylacetone (GGA) on the expression of inducible (HSP72) and constitutive (HSC70) heat shock proteins (HSPs) on retinal ganglion cells (RGCs) in a rat model of glaucoma. METHODS: Adult Wistar rats were given intraperitoneal injections of GGA at 200 mg/kg daily. Western blot analysis and immunohistochemical staining for HSP72 and HSC70 were performed after 1, 3, and 7 days of treatment with GGA. After 7 days of GGA pretreatment, intraocular pressure (IOP) was elevated unilaterally by repeated trabecular argon laser photocoagulation 5 days after intracameral injection of india ink. After the first laser photocoagulation, GGA was administered twice a week. RGC survival was evaluated after 5 weeks of elevated IOP. Immunohistochemistry and TdT-mediated biotin-dUTP nick end labeling (TUNEL) were performed after 1 week of elevated IOP. Quercetin, an inhibitor of HSP expression, was also administered to a separate group. RESULTS: There was increased expression of HSP72 in RGCs at 3 and 7 days after administration of GGA, but HSC70 was unchanged. After 5 weeks of elevated IOP, there was a 27% +/- 6% loss of RGCs. The administration of GGA significantly reduced the loss of RGCs, lessened optic nerve damage, decreased the number of TUNEL-positive cells in the RGC layer, and increased HSP72. Quercetin abolished these protective effects. CONCLUSIONS: These results demonstrate that systemic administration of GGA protects RGCs from glaucomatous damage in a rat model and suggest a novel pathway for neuroprotection in patients with glaucoma.     

经瞳孔温热疗法诱导大鼠热休克蛋白60在视盘中的表达

目的探讨经瞳孔温热疗法（TTT）阈下刺激诱导大鼠视盘中热休克蛋白（HSP）60的表达,探讨TTT对视盘组织超微结构的影响。方法采用810nm二极管激光对12周龄的BN大鼠56只右眼视盘进行阈值下TTT照射,选择激光参数为光斑直径0.5mm、持续时间60s、能量60mW;另设8只正常大鼠为对照。实验鼠分别于TTT照射后24h、72h和1周过量麻醉处死,实验眼的视盘组织切片制备后应用免疫组织化学染色法鉴别BN大鼠视盘TTT照射后HSP60的表达;Western blot法对TTT干预后HSP60在视盘组织中的表达进行半定量分析,并以吸光度（A）值表示。透射电镜下观察TTT照射后1周实验眼视盘组织的超微结构变化。结果免疫组织化学染色显示,HSP60在正常大鼠视盘局部呈弱阳性表达,TTT干预后24h、72h及1周HSP60的阳性染色明显增强,72h最强;Western blot蛋白质表达半定量分析显示,HSP60在正常大鼠视盘中的表达量为21458.13±156.32,在TTT干预后24h、72h及1周表达量分别为46907.24±10099.20、61848.02±2714.49、40738.01±5670.12,较正常大鼠视盘中的表达量明显上调,差异均有统计学意义（t=0.002、t=0.000、t=0.001,P〈0.01）,72h表达最强。阈下TTT干预后1周透射电镜下可见视盘神经纤维轴索部分髓鞘板层离散,个别轴索神经微丝、微管有溶解现象,有轻度轴膜下水肿,但神经纤维密度无明显减少。结论 TTT阈下刺激可诱导大鼠视盘中HSP60的表达,并对正常组织的超微结构产生轻度影响。     

巩膜上静脉烙闭法建立大鼠高眼压模型对视网膜微观结构的影响

目的　观察巩膜上静脉烙闭法建立的大鼠高眼压模型对视网膜微观结构的影响，为青光眼视神经损伤及保护机制提供研究基础。方法　选取不同体质量SD大鼠40只，分为A组（150~200 g）、B组（>200~250 g）、C组（>250~300 g）、D组（>300~350 g），每组各10只，分别测量3 d白天及夜间基线眼压。随机选取SD大鼠（雌雄随机，250~300 g）40只，术前测量3 d基线眼压，以右眼为实验眼，烙闭实验眼3~4支巩膜上静脉，以左眼为对照眼，于术后即刻、1~7 d、14 d、21 d、28 d分别测量实验眼和对照眼眼压。于术前及术后28 d分别用光学相干断层扫描(optical coherence tomography，OCT)仪测量视网膜厚度。于术后28 d处死大鼠，行石蜡包埋、苏木精伊红（hematoxylin eosin，HE）染色，计数视网膜神经节细胞（retinal ganglion cells，RGCs）并测量视网膜厚度。结果　不同体质量大鼠昼夜眼压比较差异均有统计学意义（均为P<0.001）。A组大鼠眼压较其他3组眼压低（均为P<0.05）。巩膜上静脉烙闭术后即刻实验眼眼压达到峰值，较对照眼高122%（P<0.001），之后缓慢下降，到术后14 d、21 d实验眼眼压较对照眼分别升高约41%、20%（均为P<0.001），到术后28 d实验眼与对照眼眼压差异无统计学意义（P>0.05）。OCT提示内层视网膜变薄（均为P<0.001）。HE染色切片结果提示RGCs数量减少，内、中、外层视网膜均变薄（均为P<0.05），且以内层变化最明显（P<0.001）。结论　大鼠基线眼压昼夜存在差异，白天眼压较夜间眼压低，低体质量（150~200 g）大鼠眼压偏低。烙闭大鼠巩膜上静脉能维持3周的眼压升高，且能使视网膜变薄、RGCs数量减少，故巩膜上静脉烙闭法是建立大鼠高眼压模型的有效方法。     

Induction of heat shock proteins 27 and 72 in retinal ganglion cells after acute pressure-induced ischaemia

Background:  We wanted to investigate whether heat shock protein (HSP) 27 and HSP 72 are induced in retinal ganglion cells (RGCs) after acute intraocular pressure (IOP)-induced ischaemia.
Methods:  Retinal ischaemia was induced by acutely increasing IOP to 100–110 mmHg for 30 or 90 min unilaterally in Sprague Dawley rats. A fluorescent tracer (fluorogold, FG) was applied to the superior colliculi to label RGCs. Twenty-four hours, 1 week or 2 weeks after of IOP elevation, rats were killed, RGCs counted, and immunohistochemical labelling of the retina was performed. HSP-positive RGCs were counted and normalized HSP RGC counts determined.
Results:  The ratio of FG-positive labelled RGCs in the experimental to the contralateral eye as a marker of RGC survival remained unchanged after 30 min of ischaemia: 1.09 ± 0.11 at 1 week, and 0.94 ± 0.28 at 2 weeks. After 90 min of ischaemia RGC survival decreased to 0.19 ± 0.14 at 1 week, and 0.20 ± 0.14 at 2 weeks. After 30 min of ischaemia, the normalized HSP 27- and HSP 72-positive RGC count was detected at highest levels (HSP 27: 5.42 ± 1.18; HSP 72: 12.23 ± 1.24) at 2 weeks compared with controls, whereas after 90 min ischaemia it was detected at higher levels at 1 week (HSP 27: 52.63 ± 3.65; HSP 72: 206.84 ± 60.38), as well as at 2 weeks (HSP 27: 89.00 ± 17.21; HSP 72: 191.00 ± 50.05).
Conclusion:  These results demonstrate an enhanced induction of HSP 27 and HSP 72 after 90 min acute IOP-induced ischaemia. In contrast to 30 min ischaemia, we showed time-dependent loss of RGCs after 90 min of ischaemia after 1 week or 2 weeks.