Protective effect of ischemic preconditioning on retinal ischemia-reperfusion injury in rats

BACKGROUND: A short period of ischemia can induce remarkable tissue resistance to the deleterious effects of subsequent ischemia and reperfusion. We performed a study to investigate the effect of ischemic preconditioning on retinal ischemia-reperfusion injury in rats. METHODS: Ten Wistar albino rats were divided into two groups of five animals (10 eyes): one group underwent 5 minutes of ischemic preconditioning (achieved by clamping the common carotid arteries at the time of vertebral artery cauterization), and the other did not (control group). In both groups, the vertebral arteries were occluded bilaterally with an electric needle coagulator under an operating microscope. Forty-eight hours later the rats were reanesthesized, and both common carotid arteries were clamped to interrupt blood flow.The duration of ischemia was 30 minutes. The clamp was then removed to enable reperfusion for 4 hours. The animals were killed by decapitation, and retinal sections were evaluated under light and electron microscopy.The signs of ischemia-reperfusion injury (cellular degeneration, vacuolization between retinal layers, increase in retinal thickness due to edema, mononuclear cell infiltration and apoptotic cell count) were recorded. RESULTS: Light microscopy of retinal sections from rats in the ischemic preconditioning group showed a well-preserved retinal structure. The mean thickness values (and standard deviation [SD]) for the inner nuclear layer (104.0 microm [2.54 microm] vs. 49.0 microm [ 10.83 microm]) and inner plexiform layer (134.8 microm [10.13 microm] vs. 88.5 microm [17.46 microm]) were significantly higher in the control group than in the preconditioning group (p = 0.009), indicating increased retinal thickness in the former group due to tissue edema resulting from ischemia-reperfusion injury.The mean mononuclear cell count (6.67 [SD 1.97] vs. 2.5 [SD 1.0]) and apoptotic cell count (18.2 [SD 5.7] vs. 5.3 [SD 1.0]) were significantly higher in the control group than in the preconditioning group (p = 0.002), indicating an inhibitory effect of ischemic preconditioning on leukocyte infiltration and apoptotic cell death. INTERPRETATION: Ischemic preconditioning attenuated ischemia-reperfusion injury in the rat retina.     

y-39983预处理对缺血-再灌注损伤大鼠视网膜的保护作用

目的:探讨ROCK抑制剂y-39983对缺血再灌注(ischemia reperfusion,IR)大鼠视网膜的保护作用。方法:SD大鼠60只随机分为正常组(n=15)、IR组(n=15)、生理盐水组(n=15)、y-39983治疗组(n=15)。正常组不做任何处理,后三组制作视网膜IR模型(前房加压灌注法),其中生理盐水组和y-39983治疗组于造模前5min分别向实验眼玻璃体腔内注入无菌生理盐水和y-39983各10μL。采用免疫组化方法检测细胞间黏附分子-1(intercellular cell adhesion molecules-1,ICAM-1)表达。荧光金逆行标记计数各组大鼠视网膜神经节细胞(retinalganglion cells,RGCs)。应用组织病理学方法和视网膜电流图评估视网膜损伤程度。结果:y-39983预处理能降低ICAM-1蛋白表达和视网膜水肿程度,并且显著提高了视网膜神经节细胞存活率及b波和O2相对恢复率,缓解IR损伤所致的内层视网膜变薄的情况。结论:y-39983能减轻视网膜IR损伤,而这一保护效应在一定程度上与其抑制ICAM-1异常表达增加有关,表明y-39983对IR损伤相关的视网膜疾病有治疗作用。     

外源性H2S预处理对大鼠RIRI细胞凋亡的影响

目的:探讨气体信号分子硫化氢(H2S)对大鼠视网膜缺血再灌注损伤(retinal ischemia-reperfusion injury,RIRI)过程中细胞凋亡及Bcl-2和Bax蛋白表达的影响。方法:以硫氢化钠(NaHS)作为H2S的供体。将54只SD大鼠随机分成正常组、视网膜缺血再灌注损伤组(RIRI组)及硫氢化钠(NaHS)干预组,后两组进一步分为再灌注后6,24,48,72h组。采用前房灌注加压的方法建立RIRI模型,TUNEL法检测视网膜神经细胞凋亡,免疫组织化学法检测视网膜组织中Bcl-2和Bax蛋白的表达。结果:细胞凋亡出现于缺血灌注后6h,并逐渐递增,24h达到高峰,48h开始下降。与RIRI组比,NaHS组Bcl-2蛋白表达增多,Bax蛋白表达减少(均P<0.05)。结论:H2S预处理可通过上调Bcl-2蛋白表达、下调Bax蛋白表达、升高Bcl-2/Bax比值从而调控细胞凋亡,对大鼠RIRI进行保护作用。     

金雀异黄酮对大鼠视网膜缺血-再灌注损伤的保护作用

目的 探讨金雀异黄酮(GEN)对大鼠视网膜缺血-再灌注(L/R)损伤的保护作用.方法 选取30只健康SPF级大鼠,按照随机数字表法将其分为假手术组、I/R组和L/R+ GEN组,每组各10只.I/R组和I/R+ GEN组大鼠采用前房灌注生理盐水升高眼压法制备视网膜I/R损伤大鼠模型,I/R组大鼠术后每天给予注射生理盐水...     

米诺环素对大鼠视网膜缺血再灌注的保护作用探讨

目的 探讨米诺环索对大鼠视网膜缺血再灌注损伤的保护作用.方法 SD大鼠88只,分为正常对照组8只,缺血组和治疗组各40只.建立视网膜缺血再灌注模型,于6、24、48、72 h检测视网膜电图(ERG)b波振幅,分光光度计测定超氧化物歧化酶(SOD),丙二醛(MDA),一氧化氮(NO)的变化,免疫组织化学检测半胱天冬酶-3(caspase-3)的表达,电镜观察超微结构.结果 与缺血组相比,治疗组可维持ERG b波振幅,升高SOD含量,降低MDA、NO含量,降低caspase-3表达,可减轻超微结构损伤(P＜0.05).结论 米诺环素可维持ERG b波振幅,调控SOD、MDA、NO,改善超微结构而保护视网膜.     

牡荆苷对大鼠视网膜缺血-再灌注损伤模型中神经节细胞的保护作用

目的:探讨牡荆苷对大鼠视网膜缺血-再灌注(RIR)引起的视网膜神经节细胞(RGCs)氧化应激损伤的保护作用及其可能的作用机制。方法:将60只SPF级雄性SD大鼠按照随机数字表法随机分为正常对照组、模型组和牡荆苷组,均以右眼为实验眼。模型组和牡荆苷组大鼠采用前房灌注方法建立RIR模型,牡荆苷组大鼠建模后每日按照25 mg...     

藏红花素对大鼠视网膜缺血-再灌注损伤的保护作用

目的　观察大鼠视网膜缺血-再灌注损伤（retinal ischemia-reperfusion injury，RIRI）时藏红花素对视网膜细胞凋亡数目、凋亡相关蛋白Caspase-3表达的影响，探讨缺血再灌注时藏红花素对视网膜的保护作用机制。方法　选取体质量200~250 g的健康雄性SD大鼠24只，随机分为4组:对照组、模型组、藏红花素低剂量组和藏红花素高剂量组，每组6只。藏红花素低剂量组、高剂量组分别于造模前3 d、30 min定时腹腔注射5 g·L^-1藏红花素5 mg·kg^-1、50 mg·kg^-1。造模成功后24 h处死大鼠并摘取眼球。使用电镜观察各组大鼠视网膜细胞结构，TUNEL染色检测视网膜凋亡细胞数量，免疫组织化学染色法观察凋亡相关蛋白Caspase-3在视网膜中的表达。结果　视网膜TUNEL染色发现，对照组视网膜组织中几乎未发现凋亡细胞的阳性表达，模型组视网膜神经节细胞层和内核层中发现大量棕黄色着色的细胞，其凋亡细胞数为（27.40±0.96）个，藏红花素低剂量组可见神经节细胞层、内核层凋亡细胞数较模型组减少，凋亡细胞数为（8.40±0.41）个，与模型组相比差异有统计学意义（P<0.01）；藏红花素高剂量组凋亡细胞数较模型组和低剂量组明显减少，凋亡细胞数为（4.30±0.47）个，和藏红花素低剂量组相比差异有统计学意义（P<0.01）。对照组大鼠视网膜组织Caspase-3染色阴性，模型组视网膜神经节细胞层可见棕黄色颗粒位于细胞浆内，藏红花素低剂量组Caspase-3蛋白表达量与模型组类似，藏红花素高剂量组Caspase-3蛋白表达量与对照组类似。结论　藏红花素能通过降低Caspase-3蛋白含量及凋亡细胞数，从而有效保护视网膜免受RIRI。     

倍他洛尔与氨基胍对大鼠视网膜缺血再灌注损伤的保护作用

目的:通过观察在大鼠急性高眼压模型中视网膜一氧化氮合成酶(nitric oxide synthase,NOS)分布及含量的变化,并检测视网膜丙二醛(malondialdehyde,MDA)水平的变化,探讨氨基胍(aminoguanidine,AG)与倍他洛尔(betaxolol)对大鼠高眼压视网膜缺血再灌注损伤的保护作用。方法:采用前房穿刺加压法建立大鼠缺血再灌注损伤模型,维持灌注时间60min。将各组右眼球经视神经矢状切片标本做HE染色进行视网膜组织学观察,还原型尼克酰胺嘌呤二核苷酸磷酸-黄递酶(NADPH-d)法检测视网膜NOS染色阳性的细胞数,硫代巴比妥酸(thiobarbituric acid,TBA)法测定各组左眼球视网膜MDA含量。结果:各组视网膜均有NOS表达,NOS阳性细胞在视网膜主要分布于视网膜节细胞层(ganglion cell layer,GCL)、内丛状层(inner plexiform layer,IPL)、内核层(inner nuclearlayer,INL),200倍视野计数生理盐水组视网膜GCL的NOS阳性细胞数明显高于空白对照组(P<0.01);AG与betaxolol药物治疗各组的NOS阳性细胞数较生理盐水组减少(P<0.05);视网膜NOS阳性细胞数与视网膜MDA含量增减呈正相关性(r=0.69,P<0.01)。结论:AG通过对诱导型NOS的抑制在大鼠高眼压诱导视网膜损伤中起到视神经保护作用。betaxolol通过抑制钙通道,使NO的生成减少,增加抗氧化能力,从而起神经保护作用。     

补阳还五汤对大鼠视网膜缺血再灌注损伤的作用

目的:观察补阳还五汤(Buyang Huanwu Decoction,BYH-WT)对Wistar大鼠视网膜、视神经缺血再灌注损伤是否具有保护作用,并进一步探讨补阳还五汤的作用机理。方法:使用Wistar大鼠建立视网膜、视神经缺血再灌注损伤模型。模型建立后,将大鼠随机分为2组:(1)中药组:缺血60min后开始灌服BYHWT水煎剂[10g/(kg·d)];(2)对照组:缺血60min后开始灌服平衡盐液[10g/(kg.d)]。两组分别在灌服后24h、6wk取材行视网膜和视神经的超微结构观察。结果:中药组24h和对照组的视网膜及视神经的超微结构均有明显病变,但中药组较对照组变化轻微。中药组6wk的视网膜及视神经的病变基本恢复正常;对照组仍存明显病变。结论:补阳还五汤对大鼠视网膜、视神经缺血再灌注损伤具有保护作用。     

视网膜缺血--再灌注损伤的保护

视网膜缺血-再灌注损伤是目前研究较多的一个课题,其损伤机制复杂,目前通过各种实验研究探索其损伤机制以及减轻或防止缺血-再灌注损伤的药物和方法很多.现就视网膜缺血-再灌注损伤的保护机制进行总结归纳.     

Quantitative analysis of leukocyte dynamics in retinal microcirculation of rats with short-term ischemia-reperfusion injury.

PURPOSE: To characterize the time course of complete recovery of leukocyte velocities in the retinal microcirculation of rats from short-term (5-minute) retinal ischemia. METHODS: After 5 minutes of retinal ischemia produced by clamping the optic nerve, resulting in the occlusion of both central retinal artery and the central retinal vein, we used acridine orange (AO) and a scanning laser ophthalmoscope (SLO) to observe the velocities of leukocytes in precapillary arteriole ( v(a)), capillary (v(c)) and postcapillary venule (v(v)). Measurements were taken at reperfusion time points of 5, 10, 15, 20, 30, 40, 50, 60 and 80 minutes for the ischemic eyes and at 12, 22, 42 and 62 minutes for the control eyes, respectively. RESULTS: Each control velocity was arteriole 25.1 +/- 4.3 mm/ s; venule 16.9 +/- 3.2 mm/s; and capillary 1.54 +/- 0.31 mm/s, respectively. The leukocyte velocities after 5 minutes of ischemia in arteriole and venule recovered completely within 80 minutes of reperfusion; however, the recovery patterns were different. The recovery pattern showed a biphasic increase in arterioles and a monophasic increase in venules. The velocity in capillaries half recovered rapidly, within 5 minutes of reperfusion, but the subsequent recovery was slower and was not complete even at 80 minutes of reperfusion. CONCLUSIONS: In this study, leukocyte velocities in arterioles, venules and capillaries exhibited different recovery patterns following retinal ischemia and subsequent reperfusion. Capillaries, at least within 80 minutes of reperfusion, may have difficulty recovering completely from even short-term (5-minute) ischemia.     

复方樟柳碱对大鼠视网膜缺血再灌注损伤的保护作用

目的:探讨复方樟柳碱对大鼠视网膜缺血再灌注损伤的治疗作用。方法:将成年雌性Wistar大鼠随机分成正常对照组,造模组和复方樟柳碱组,每组10只。采用前房灌注升高眼压制作急性视网膜缺血模型。观察1,3,7d视网膜电图a波b波的恢复情况。每组随机取2只大鼠造模眼球光镜、电镜下观察视网膜形态结构的变化,以及神经节细胞线粒体的变化。结果:复方樟柳碱组较造模组神经节细胞线粒体肿胀程度轻,b波明显恢复,同造模组与正常组间b波的恢复比较差异有显著统计学意义(P<0.01)。结论:复方樟柳碱可减轻大鼠视网膜缺血再灌注损伤,有神经细胞保护作用。     

L-carnitine in experimental retinal ischemia-reperfusion injury

The effect of L-carnitine on retinal ischemia-reperfusion injury was evaluated in guinea pigs. 90 min of pressure-induced retinal ischemia followed by 24 h of reperfusion was established in both eyes of 2 groups of animals receiving either L-carnitine (100 mg/kg repeated in 5 doses) or saline intraperitoneally. After enucleation of all the eyes, including those of a control group, malonyldialdehyde (MDA) levels and the thickness of the retinal tissue were measured in 3 groups. The mean MDA value and the tissue thickness of the L-carnitine-treated group were statistically insignificant versus the control group (p > 0.05 and p > 0.05, respectively). However, these values were significantly different in the group receiving saline versus the control group and that receiving L-carnitine (p < 0.001, p < 0.001 and p < 0.001, p < 0.001 respectively). L-Carnitine might be an alternative drug for ischemia-reperfusion injury of the retina.     

葛根素对实验性视网膜缺血-再灌注损伤后视神经的保护作用

目的探讨葛根素对实验性高眼压视网膜缺血-再灌注损伤后视神经的保护作用及其机制。方法用眼内灌注法前房灌注林格氏液制成急性高眼压视网膜缺血-再灌注损伤模型。将70只SD大鼠随机分为正常对照组(10只),葛根素治疗组(30只)和模型组(30只)。其中后2组根据再灌注的时间不同分为1d、3d、7d组,每组10只大鼠。治疗组经大鼠腹腔注射葛根素注射液(60mg·kg-1),模型组经大鼠腹腔注射生理盐水(10mL·kg-1)。利用免疫组织化学法检测各组大鼠视网膜内一氧化氮合酶(neural nitrogenoxide synthase,nNOS)的表达,以及硫代巴比妥酸法测量丙二醛(malonaldialdehyde,MDA)含量,黄嘌呤氧化酶法测超氧化物歧化酶(superoxide dismutase,SOD)活性。结果从再灌注1d开始,模型组视网膜内nNOS阳性表达明显增多,MDA水平持续升高,SOD活性持续下降,其差异与正常对照组相比,有统计学意义(P<0.01)。与模型组相比,再灌注各时段葛根素治疗组nNOS阳性神经元明显减少(P<0.01),MDA含量降低(P<0.01),SOD活性升高(P<0.01),其中nNOS阳性神经元与正常对照组相比,无统计学意义(P>0.05)。结论葛根素可通过提高视网膜组织中SOD活性,降低MDA含量,以及增加组织中nNOS表达,对大鼠实验性高眼压视网膜缺血-再灌注损伤有一定的保护作用。     

葡萄籽原花青素对大鼠视网膜缺血-再灌注损伤的保护作用

目的　探讨葡萄籽原花青素（grape seed proanthocyanidin extract，GSPE）对大鼠视网膜缺血-再灌注损伤（retinal ischemia-reperfusion injury，RIRI）的保护作用及其机制。方法　将120只大鼠分为假手术组（Sham组，灌胃生理盐水）、模型组（RIRI组，眼内灌注加压法制备，灌胃生理盐水）及GSPE低、中、高剂量组（GSPE-L组、GSPE-M组、GSPE-H组，灌胃0.13 g·kg^-1 GSPE、0.25 g·kg^-1 GSPE、0.50 g·kg^-1 GSPE）、阳性对照组（α-LA组,灌胃100 mg·kg^-1 α-硫酸锌）。采用苏木精-伊红（HE）染色观察各组大鼠视网膜组织形态学变化情况；ELISA法检测血清肿瘤坏死因子-α（TNF-α）、iNOS、白细胞介素-6（IL-6）水平，氮蓝四唑显色法检测血清超氧化物歧化酶（SOD）活性；双抗体夹心法检测血清丙二醛（MDA）水平，铁离子还原法检测活性氧（ROS）水平；TUNEL法检测各组大鼠视网膜组织神经细胞凋亡；免疫组织化学法检测各组大鼠视网膜组织中核因子E2-相关因子2（Nrf2）、血红素加氧酶-1（HO-1）、Caspase-3表达情况；Western blot法检测各组大鼠视网膜组织中细胞外信号调节激酶1/2（ERK1/2）、p-ERK1/2表达情况。结果　GSPE-L组、GSPE-M组、GSPE-H组、α-LA组、RIRI组和Sham组视网膜厚度分别为（139.31±11.43）μm、（127.05±12.73）μm、（113.16±13.25）μm、（110.58±13.47）μm、（161.48±10.26）μm、（92.35±16.54）μm,Nrf2蛋白阳性表达率分别为（29.93±4.21）%、（34.06±5.17）%、（43.12±7.23）%、（45.35±7.46）%、（11.86±3.19）%、（52.27±8.36）%，ERK1/2蛋白磷酸化水平分别为0.41±0.05、0.62±0.07、0.89±0.09、0.92±0.05、0.23±0.04、1.16±0.25，RIRI组与Sham组比较，差异均有统计学意义（均为P<0.05）， GSPE-L组、GSPE-M组、GSPE-H组、α-LA组与RIRI组比较，差异均有统计学意义（均为P<0.05），且GSPE表现出剂量依赖性。与Sham组相比，RIRI组神经细胞凋亡率、Caspase-3阳性表达率、TNF-α、IL-6、iNOS、MDA、ROS水平显著升高，HO-1阳性表达率、SOD水平显著降低（均为P<0.05）；与RIRI组相比，GSPE-L组、GSPE-M组、GSPE-H组、α-LA组神经细胞凋亡率、Caspase-3阳性表达率、TNF-α、IL-6、iNOS、MDA、ROS水平显著降低，HO-1阳性表达率、SOD水平显著升高，且GSPE表现出剂量依赖性剂量依赖性（均为P<0.05）。结论　GSPE能够抑制视网膜组织神经细胞凋亡，保护视网膜组织，其作用机制可能与ERK/Nrf2/HO-1通路活化有关。     

腺病毒载体介导的色素上皮衍生因子对大鼠视网膜缺血再灌注损伤的保护作用

目的:观察重组腺病毒介导的色素上皮衍生因子(Ad-PEDF)对大鼠视网膜缺血再灌注损伤的保护作用及机制。方法:选用健康大鼠96只,随机分为正常组、缺血再灌注组、缺血再灌注+Ad-CMV组,缺血再灌注+Ad-PEDF组,以前房加压的方法制备大鼠视网膜缺血再灌注模型,缺血再灌注+Ad-CMV组,缺血再灌注+Ad-PEDF组分别玻璃体腔注射Ad-CMV或Ad-PEDF1μL(滴度3.8×109/PFU),每组按照时间点12,24,72,168h,为4亚组,光学显微镜观察视网膜组织切片情况,并测量视网膜内层厚度及神经节细胞层神经节细胞数量。以TUNEL方法观察大鼠视网膜神经节细胞凋亡情况。结果:Ad-PEDF组视网膜内层厚度均超过缺血组及缺血+Ad-CMV组,Ad-PEDF组神经节细胞数目多于缺血组及Ad-CMV组,Ad-PEDF组视网膜神经节细胞凋亡细胞少于缺血组及Ad-CMV组,凋亡程度减轻,上述差异均具有显著性(P<0.05)。结论:腺病毒介导的色素上皮衍生因子玻璃体腔注射能够恢复大鼠视网膜缺血再灌注损伤所致的视网膜内层厚度降低,神经节细胞密度减少,具有保护作用。     

倍他洛尔对实验性视网膜缺血再灌注损伤后 视神经的保护作用

目的探讨倍他洛尔对实验性视网膜缺血再灌注损伤后视神经的保护作用及其可能的作用机制。方法采用升高眼内压的方法，制作大鼠实验性视网膜缺血再灌注损伤模型。将68只SD大鼠随机分为正常对照组（8只）、0.25%倍他洛尔治疗组（30只）和生理盐水对照组（30只）。其中后两组根据再灌注的不同时间各分为1、3、7 d组，每组10只大鼠。治疗组鼠右眼滴入0.25%倍他洛尔眼药水，生理盐水对照组鼠右眼滴入生理盐水。观察治疗组和生理盐水对照组及正常对照组鼠视网膜电图（ERG）b波振幅及光学显微镜、电子显微镜下视网膜结构变化；免疫组织化学法检测神经性一氧化氮合酶（nNOS）的表达,分光光度法测定丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性。结果从再灌注1 d开始，生理盐水对照组ERG的b波振幅持续下降，病理组织损害逐渐加重，视网膜中nNOS阳性表达明显增多，MDA水平持续升高，SOD水平持续下降，其差异与正常对照组比较均有统计学意义（P＜0.01）；与生理盐水对照组相比，再灌注各时段倍他洛尔治疗组ERG的 b波振幅明显恢复（P＜0.01），病理组织损害明显减轻，nNOS阳性神经元明显减少（P＜0.01），MDA含量降低（P＜0.01），SOD活性升高（P＜0.01），其中nNOS阳性神经元与正常对照组的差异无统计学意义（P＞0.05）。结论倍他洛尔可能通过减少细胞内Ca²⁺超载，抑制NO的产生和提高抗氧化能力，对大鼠实验性视网膜缺血再灌注损伤有一定的保护作用。(中华眼底病杂志,2005,21:249-252)      

Protection of retinal ganglion cells against optic nerve injury by induction of ischemic preconditioning

AIM: To explore if ischemic preconditioning (IPC) can enhance the survival of retinal ganglion cells (RGCs) after optic nerve axotomy. METHODS: Twenty-four hours prior to retinal ischemia 60min or axotomy, IPC was applied for ten minutes in groups of (n=72) animals. The survival of RGCs, the cellular expression of heat shock protein 27 (HSP27) and heat shock protein 70 (HSP70) and the numbers of retinal microglia in the different groups were quantified at 7 and 14d post-injury. The cellular expression of HSP27 and HSP70 and changes in the numbers of retinal microglia were quantified to detect the possible mechanism of the protection of the IPC. RESULTS: Ten minutes of IPC promoted RGC survival in both the optic nerve injury (IPC-ONT) and the retinal ischemia 60min (IPC-IR60) groups, examined at 7d and 14d post-injury. Microglial proliferation showed little correlation with the extent of benefit effects of IPC on the rescue of RGCs. The number of HSP27-positive RGCs was significantly higher in the IPC-ONT group than in the sham IPC-ONT group, although the percentage of HSP27-positive RGCs did not significantly differ between groups. For the IPC-IR60 group, neither the number nor the percentage of the HSP27-positive RGCs differed significantly between the IPC and the sham-operated groups. The number of HSP70-positive RGCs was significantly higher for both the IPC-ONT and the IPC-IR60 experimental groups, but the percentages did not differ. CONCLUSION: The induction of IPC enhances the survival of RGCs against both axotomy and retinal ischemia.     

藏红花素对视网膜缺血再灌注损伤小鼠视网膜神经节细胞的保护作用及其机制研究

目的　研究藏红花素对视网膜缺血再灌注损伤（RIRI）小鼠视网膜神经节细胞（RGC）的保护作用及其机制。方法　将144只C57BL/6小鼠随机分为3组:假手术组、模型组、藏红花素治疗组。模型组和藏红花素治疗组小鼠建立RIRI模型,藏红花素治疗组小鼠造模前30 min腹腔注射50 mg·kg^-1藏红花素。RIRI后14 d,视网膜铺片染色比较各组小鼠RGC密度差异。RIRI后24 h,HE染色比较各组小鼠视网膜内层厚度差异。于RIRI后不同时间点（0 h、3 h、6 h、9 h、12 h、15 h）取各组小鼠视网膜组织,通过多重基因定量分析系统检测NLRP3、ASC、Caspase-1、白细胞介素-1β（IL-1β） mRNA的表达变化。RIRI后6 h和12 h取各组小鼠视网膜组织,Western blot检测NLRP3、ASC、Caspase-1、IL-1β蛋白的表达,ELISA检测IL-1β蛋白的含量,并对比分析。结果　小鼠RIRI后14 d,视网膜铺片染色结果显示,藏红花素治疗组较模型组小鼠RGC密度增加约18.5%（P<0.05）。RIRI后24 h,HE染色结果显示,藏红花素治疗组小鼠视网膜内层厚度较模型组显著降低（P<0.01）。多重定量分析系统检测结果显示,RIRI后6 h、9 h及12 h,藏红花素治疗组小鼠视网膜组织中Caspase-1以及IL-1β mRNA表达较模型组均显著降低（均为P<0.05)。Western blot检测结果显示,藏红花素治疗组小鼠视网膜组织中Caspase-1以及IL-1β蛋白表达较模型组均显著降低（均为P<0.05)。RIRI后6 h、12 h,模型组小鼠视网膜组织中NLRP3、ASC mRNA和蛋白表达与假手术组相比无显著变化（均为P>0.05)。ELISA检测结果进一步证实,RIRI后6 h和12 h,藏红花素治疗组小鼠视网膜组织中IL-1β蛋白含量较模型组均显著降低（均为P<0.05)。结论　藏红花素通过抑制Caspase-1和IL-1β表达保护RIRI小鼠RGC。