牛磺酸对家兔缺血/再灌注心肌细胞凋亡的影响

目的:研究牛磺酸(Tau)对家兔缺血/再灌注损伤心肌细胞凋亡的影响.方法:阻断家兔心脏左冠状动脉前降支45 min,再灌注180 min引起心肌缺血/再灌注损伤,在心肌缺血前5 min耳缘静脉注射牛磺酸(200mg/kg),应用DNA片段原位末端标记法 (TUNEL染色),DNA凝胶电泳和流式细胞仪(FCM)观测心肌细胞凋亡.结果:琼脂糖凝胶电泳显示损伤对照组(I/R) 心肌DNA呈云梯状改变,而Tau I/R组无此改变.与损伤对照组(I/R) 比较,Tau I/R组缺血心肌凋亡细胞明显减少(TUNEL染色).流式细胞仪测定I/R组及Tau I/R组缺血心肌凋亡率分别为17.66%±1.54%和4.86%±1.23%.I/R组的缺血心肌Fas和Bax蛋白表达较非缺血心肌高 (P<0.01),Bcl-2/Bax比例较非缺血心肌低(P<0.01);而在Tau I/R组,Fas和Bax蛋白表达较I/R组的低 (P<0.01),Bcl-2/Bax比例较I/R组高(P<0.01).结论:牛磺酸可减少I/R家兔心肌细胞凋亡,其机制与调控凋亡相关基因 Fas,Bax和Bcl-2的蛋白表达有关.     

Inhibition of cathepsin S attenuates myocardial ischemia/reperfusion injury by suppressing inflammation and apoptosis

Myocardial ischemia/reperfusion (I/R) injury leads to high mortality and morbidity due to the incomplete understanding of the underlying mechanism and the consequent lack of effective therapy. The present study revealed and validated key candidate genes in relation to inflammation and apoptosis pathways underlying myocardial I/R injury. Cathepsin S was identified as the top hub protein based on the protein–protein interaction analysis, and, thus, its role during myocardial I/R injury was further investigated. Myocardial I/R in mice resulted in significantly increased levels of myocardial injury biomarkers (cardiac troponin I, lactic dehydrogenase, and creatinine kinase‐MB) and inflammatory cytokines (interleukin‐1β [IL‐1β], IL‐6, and tumor necrosis factor‐α), elevated apoptosis rate, and upregulated protein expression of cleaved caspase‐8, cleaved caspase‐3, and cleaved poly ADP‐ribose polymerase. These abovementioned changes were blocked by two different selective cathepsin S inhibitors, LY3000328 or MIV‐247. Moreover, Kaplan–Meier survival plot showed that cathepsin S inhibition improved 21‐day survival rate following myocardial I/R injury. This study demonstrated that the inhibition of cathepsin S alleviated myocardial I/R‐induced injury by suppressing inflammation and apoptosis, which may be used in clinical applications of cardioprotection.     

缺血后处理对大鼠再灌注损伤肺细胞凋亡的影响

目的：探讨缺血后处理对再灌注损伤肺细胞凋亡的影响。方法：健康雄性sD大鼠24只,随机分为对照组（C组）、缺血／再灌注组（I／n组）和缺血后处理组（IPostC组）（n=8）。对比观察各组血清中丙二醛（MDA）、超氧化物歧化酶（SOD）、髓过氧化物酶（MPO）活力及含量变化,原位缺口末端标记法（TUNEL）检测肺组织细胞凋亡情况,免疫组化及RT-PCR法检测肺组织中Bax、Bcl一2蛋白和基因的表达。结果：I／R组与c组相比,MDA含量、MPO活力明显升高,SOD活力明显下降（均P〈0．01）,肺组织原位细胞凋亡检测示I／R组凋亡指数（AI）（39．03±3．46）显著高于C组（2．88±0．34）,Bcl-2／Bax比值在蛋白和基因水平明显降低（均P〈0．01）;IPostC组与I／R组相比MDA含量显著降低（P〈0．05）,MPO活力显著降低（P〈0．01）,SOD活性升高（P〈0．01）,AI为8．03±0．88显著低于L／R组,并能明显升高Bcl-2／Bax比值（均P〈0．01）。结论：缺血后处理通过减轻脂质过氧化反应及中性粒细胞聚集,降低Bax／Bel．2比值,使肺组织细胞凋亡减少,从而有效地减轻肺缺血／再灌注损伤。     

Hydrogen-rich saline protects against intestinal ischemia/reperfusion injury in rats

Hydrogen gas was reported to reduce reactive oxygen species and alleviate cerebral, myocardial and hepatic ischemia/reperfusion (I/R) injuries. This paper studied the effect of hydrogen-rich saline, which was easier for clinical application, on the intestinal I/R injury. Model of intestinal I/R injury was induced in male Sprague-Dawley rats. Physiological saline, hydrogen-rich saline or nitrogen-rich saline (5 ml/kg) was administered via intravenous infusion at 10 min before reperfusion, respectively. The intestine damage was detected microscopically and was assessed by Chiu score system after I/R injury. In addition, serum DAO activity, TNF-α, IL-1β and IL-6 levels, tissue MDA, protein carbonyl and MPO activity were all increased significantly by I/R injury. Hydrogen-rich saline reduced these markers and relieved morphological intestinal injury, while no significant reduction was observed in the nitrogen-rich saline-treated animals. In conclusion, hydrogen-rich saline protected the small intestine against I/R injury, possibly by reduction of inflammation and oxidative stress.     

异丙酚对离体大鼠心肌缺血、再灌注损伤后细胞凋亡及其机制研究

目的：观察异丙酚对离体大鼠心肌缺血/再灌注损伤的影响并从氧化应激和线粒体介导的凋亡方面探讨其作用机制。方法：应用Langendorff离体心脏灌注系统建立心肌缺血/再灌注损伤模型。40只SD大鼠随机分为正常对照组、缺血/再灌注模型（I/R）组、异丙酚15、30、60μmol.L-1组。除正常对照组外,各组分别平衡灌注20 min后,常温全心停灌25 min,再灌注30 min。Powerlab/8s仪记录各组平衡末、缺血前及再灌30 min时的各项心功能指标并测定冠脉流出液中乳酸脱氢酶（LDH）、肌酸激酶（CK）活性;检测心肌线粒体活力、膜肿胀度、锰超氧化物岐化酶（Mn-SOD）活性和丙二醛（MDA）含量;流式细胞仪检测心肌细胞凋亡;流式细胞术检测Bcl-2和Bax的表达,免疫组化法测定天冬氨酸特异的半胱氨酸蛋白酶（caspase）-3,9,8蛋白的表达。结果：与I/R组相比,异丙酚30、60μmol.L-1能明显改善缺血/再灌注后的心功能,减弱冠脉流出液中LDH、CK的活性（P〈0.05）;心肌线粒体活力有所恢复,膜肿胀度减轻,Mn-SOD活性升高,MDA生成明显减少（P〈0.05）,心肌细胞凋亡明显减少,Bcl-2表达上调,Bax表达下调,caspase-3,9阳性表达细胞数明显减少（P〈0.05）。结论：异丙酚明显减轻缺血/再灌注所致的心肌线粒体的过氧化损伤,抑制线粒体途径的凋亡,可能是其心肌保护作用机制之一。     

白藜芦醇甙对大鼠心脏缺血/再灌注损伤的保护作用

本文利用冠脉结扎/放松方法和Langendorff灌注技术,建立在体和离体大鼠心脏缺血/再灌注(ischemia/reperfusion,I/R)损伤模型,探讨白藜芦醇甙(polydatin)对大鼠I/R心肌损伤的保护作用及其机制.观察白藜芦醇甙对缺血和再灌注心律失常、心肌梗死面积、心脏收缩功能、心肌超氧化物歧化酶(superoxide dismutase,SOD)活性、丙二醛(malondialdehyde,MDA)含量、NO含量以及一氧化氮合酶(nitric oxide synthase,NOS)活性的影响.结果显示:与对照组相比,白藜芦醇甙组大鼠缺血和再灌注心律失常明显降低(P<0.05,P<0.01);心肌梗死面积显著减少(P相似文献   

锌对缺血／再灌注肝脏自由基含量和细胞凋亡的影响

目的：观察补锌对缺血再灌注（HIR）大鼠肝脏自由基含量及细胞凋亡的影响。探讨补锌保护肝损伤的机制。方法：用荧光分光光度法测定血清MDA含量;用电子自旋共振法测定肝脏自由基浓度;用流式细胞术检测肝细胞凋亡。结果：HIR组大鼠血清MDA水平和肝自由基产生均增加,补锌后降低;肝脏缺血再灌注后肝细胞凋亡率达到57.72%,补锌后降低40.85%。结论：减少自由基产生和抑制细胞凋亡是锌保护肝缺血再灌注损伤的重要机制。     

早期跑步运动对大鼠脑缺血/再灌注损伤后神经行为与神经元凋亡的影响

目的: 探讨早期跑步运动对大鼠脑缺血后神经行为与神经元凋亡的影响。方法:雄性SD大鼠随机分为4组:假手术+安静组(Sham-St、假手术+运动组(Sham-Ex)、缺血(大脑中动脉闭塞(MCAO) +运动组((MCAO -Ex)和缺血+安静组(MCAO-St),每组15只。MCAO-Ex 和 MCAO-St 组大鼠行MCAO 60 min,再灌注2 d后,MCAO-Ex 和Sham-Ex大鼠在跑步机上进行5 d的30 min/d跑步运动(15 m/min),之后进行神经行为学评价,最后大鼠断头取脑进行TTC方法染色,评估各组大鼠梗死体积以及缺血半影Caspase-3和TUNEL阳性细胞表达水平。结果:与Sham-St相比,MCAO-St和MCAO-Ex大鼠缺血半影区Caspase-3表达均显著升高 (P＜0.05);与MCAO-St 组大鼠相比,MCAO-Ex组大鼠脑梗死体积明显减少,大鼠神经功能评分明显改善,大鼠缺血半影区Caspase-3和TUNEL阳性细胞表达水平显著降低 (P＜0.05)。结论: 早期运动可能通过抑制大鼠脑缺血后神经元凋亡发挥神经保护作用。     

蛋白激酶C活化对L-6TG大鼠肌母细胞缺血/再灌注损伤中细胞凋亡的影响

目的:蛋白激酶C(PKC)活化对L-6TG大鼠肌母细胞缺血/再灌注损伤过程中细胞凋亡的影响.方法:将培养的L-6TG大鼠肌母细胞随机分为3组:①正常对照组(C组);②缺血/再灌注组(I/R组);③PMA 缺血/再灌注组(PMA组).观测了细胞内SOD、XOD、Ca2 含量的变化;采用MTT法检测线粒体的功能;利用流式细胞仪和细胞DNA电泳结果检测细胞凋亡情况;采用免疫组织化学的方法检测caspase-3的蛋白表达情况,结合自动图像分析系统对其结果进行定量分析.结果:蛋白激酶C活化可显著降低L-6TG大鼠肌母细胞I/R 4 h后细胞内XOD、Ca2 含量及凋亡细胞百分率,增加细胞内SOD活性及线粒体呼吸功能,DNA电泳无梯状条带出现,caspase-3的表达明显下调.结论:蛋白激酶C活化可明显减轻L-6TG大鼠肌母细胞缺血再灌注损伤后的细胞凋亡的发生,其机制可能与减轻氧化损伤、调节细胞内钙稳态、减轻线粒体损伤、减少caspase-3表达有关.     

The effect of quercetin on renal ischemia and reperfusion injury in the rat

Renal ischemia-reperfusion injury occurs in many clinical conditions such as hypovolemic shock, thromboembolism, injury and after renal transplantation. Under these conditions, ROS are considered to be the reason for cellular damage. Bioflavonoids have antioxidant and renoprotective properties. We studied the effect of quercetin, a bioflavonoid, on ischemia and reperfusion in rats. The rats (n = 28) were separated into three groups. Group I was the control group. Animals in groups II (IR) and III (IR + Q) underwent 30 min ischemia and 45 min reperfusion, respectively. Rats, in group III, also received 50 mg kg(-1) quercetin before 45 min of reperfusion. The activities of SOD, CAT, GPx, and concentrations of GSH and GSSGR were determined in renal cortex and erythrocytes. Also, the levels of MDA in renal cortex and plasma, and XO in renal cortex were measured in these groups. The renal cortex XO levels in the IR group were higher than that of the control and IR+Q groups (p<0.001). The renal cortex and plasma MDA levels in the IR group were also found to be higher than the control and IR+Q groups (p<0.01, and p<0.001, respectively). However, a decrease in MAD level of the IR+Q group was found in renal cortex and erythrocytes. In addition, SOD, CAT, and GPx activities in renal cortex and erythrocytes of quercetin-treated animals were enhanced compared to animals of the IR group. Furthermore, there were no significant differences in the SOD, CAT, and GPx activities of the control and IR+Q group. A reduction of GSH and GSSGR levels in IR and IR+Q groups was detected but no significant differences were found between these groups. This study stresses that high concentration of ROS leads to renal ischemia and reperfusion, and quercetin reduces the renal injury by preventing the oxidative stress dependent on ischemia and reperfusion. Quercetin may be used in renal transplantation as an antioxidant drug.     

银杏提取物对大鼠肺缺血/再灌注损伤的保护作用

目的：观察银杏提取物（EGB）对大鼠体外循环肺缺血／再灌注损伤（I／R）的保护作用。方法：建立离体大鼠肺灌流模型．SD大鼠随机分成假手术组（Sham）、I／R组和EGB组,观察大鼠肺组织形态学改变、分别测定肺组织匀浆及灌流液中超氧化物歧化醇（SOD）、丙二醛（MDA）的含量、肺湿干重比（W／D）和平均肺动脉压（MPAP）。结果：HE染色显示EGB组肺损伤明显减轻、肺组织湿／干重比和MPAP显著低于I／R组：EGB组肺脏灌流液和组织匀浆中SOD的活性显著高于I／R组,MDA含量则显著低于I／R组。结论：EGB对大鼠肺I／R损伤具有保护作用。     

高铁血红素对心肌缺血／再灌注损伤的防护作用及其机制

目的：在大鼠急性心肌缺血／再灌ii（I／R）模型上,观察高铁血红素在钙激活中性蛋白酶（calpain）介导的心肌I／R损伤中的作用。并初步探讨其可能的机制。方法：64只雄性SD大鼠随机8组（n：8）：假手术组（sham组）、（I／R）组、MDL28170＋I／R组、单纯MDL28170组、高铁血红素＋I／R组、单纯高铁血红素组、锌原卟啉Ⅸ＋高铁血红素＋I／R组、单纯锌原卟啉Ⅸ组。采用大鼠离体心脏Langendorff灌流技术,心脏I／R后,测定左室发展压（LVDP）、心肌梗死面积、冠脉流出液中的乳酸脱氢酶（LDH）释放量。检测calpain、血红素氧化酶（HO）、和半胱氨酸天冬氨酸蛋白酶3（caspase3）活性。Westernblot观察心肌钙蛋白酶抑制蛋白（calpastatin）蛋白表达。结果：①心肌I／R后,calpain、caspase3活性明显增高。calpain抑制剂MDL28170可抑制I／R诱导的LDH释放量增加,增高LVDP,缩小心肌梗死面积。②与单纯I／R组相比,大鼠预先给予高铁血红素后,心脏HO-1活性增加,calpain和caspase3活性下降。同时,LDH释放量减少,LVDP明显增高,心肌梗死面积缩小。③I／R组心肌calpastatin表达量明显低于对照组,高铁血红素组大鼠calpastatin表达量增高。HO-1的抑制剂锌原卟啉Ⅸ可取消高铁血红素对calpastain表达量的影响,并取消其心肌保护作用。结论：高铁血红素预处理可通过抑制calpain的激活,减轻大鼠心肌I／R损伤,其机制可能与增加calpastatin蛋白表达有关。     

大鼠肢体缺血预处理对肝缺血/再灌注损伤的保护作用

目的：研究肢体缺血预处理对大鼠肝缺血/再灌注损伤是否具有保护作用。方法：雄性SD大鼠32只,随机分为对照组（S组）;缺血/再灌注组（I/R组）;经典缺血预处理组（IPC组）;肢体缺血预处理组（远端缺血预处理组,RPC组）。S组仅行开腹,不作其他处理;IPC组以肝缺血5min作预处理;RPC组以双后肢缺血5min,反复3次作预处理,2个预处理组及I/R组均行肝缺血1h再灌注3h。取血用于血清谷丙转氨酶（ALT）与血清谷草转氨酶（AST）检测。切取肝组织用于测定湿干比（W/D）、中性粒细胞（PMN）计数及观察显微、超微结构的变化。结果：与I/R组比较,IPC组,RPC组ALT,AST,W/D值,及PMN计数均明显降低（P〈0.01）,肝脏的显微及超微结构损伤减轻。结论：肢体缺血预处理对大鼠肝脏I/R损伤有明显的保护作用,强度与经典缺血预处理相当,其机制可能与抑制肝脏炎症反应、减轻肝脏水肿、改善肝组织微循环有关。     

Current knowledge on oxidative stress in hepatic ischemia/reperfusion

Abstract

Ischemia/reperfusion (I/R) injury associated with hepatic resections and liver transplantation remains a serious complication in clinical practice, despite several attempts to solve the problem. The redox balance, which is pivotal for normal function and integrity of tissues, is dysregulated during I/R, leading to an accumulation of reactive oxygen species (ROS). Formation of ROS and oxidant stress are the disease mechanisms most commonly invoked in hepatic I/R injury. The present review examines published results regarding possible sources of ROS and their effects in the context of I/R injury. We also review the effect of oxidative stress on marginal livers, which are more vulnerable to I/R-induced oxidative stress. Strategies to improve the viability of marginal livers could reduce the risk of dysfunction after surgery and increase the number of organs suitable for transplantation. The review also considers the therapeutic strategies developed in recent years to reduce the oxidative stress induced by hepatic I/R, and we seek to explain why some of them have not been applied clinically. New antioxidant strategies that have yielded promising results for hepatic I/R injury are discussed.     

Effects of molsidomine on retinal ischemia/reperfusion injury in rabbits

We investigated the effect of molsidomine (MOL) on ischemia/reperfusion (I/R) injury. Rabbits were assigned to four groups: group 1, sham; group 2, I/R; group 3, MOL treatment for 4 days after I/R; group 4, MOL treatment for 1 day before I/R and 3 days after I/R. Retinal I/R was produced by elevating the intraocular pressure to 150 mm Hg for 60 min. Seven days after I/R, the eyes were enucleated. Retinal changes were examined using histochemistry. The levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) also were measured. We found a significant increase in the thickness of the outer nuclear layer of group 3 compared to the other groups. In groups 3 and 4, caspase-3 stained cells in the ganglion cell layer were decreased compared to group 2. We found a significant increase in caspase-3 stained cells in the inner nuclear layer (INL) of group 2 compared to the other groups. We found a significant increase in caspase-3 stained cells in group 3 compared to group 4 in the INL. The MDA level in group 2 was significantly higher than group 1 and MOL significantly decreased MDA levels in groups 3 and 4. We found that MOL protected the retina from I/R injury by enhancing antioxidative effects and inhibiting apoptosis of retinal cells.     

N-乙酰-L-半胱氨酸减轻大鼠胃缺血/再灌注损伤的机制

为研究N-乙酰-L-半胱氨酸(N-acetylcysteine,NAC)减轻大鼠胃缺血/再灌注(gastric ischemia/reperfusion,GI/R)损伤的机制,在大鼠股静脉注射NAC(150mg/kg),夹闭大鼠腹腔动脉30min,再灌注1h制备GI/R模型。取胃后计数胃黏膜损伤指数(gastric mucosal damage index,GMDI),用原位检测(TUNEL)法观察胃黏膜细胞的凋亡,用免疫印迹法测定胃黏膜组织中p-ERK,p-JNK和NF-κB的表达,用RT-PCR法检测TNF-α,Caspase-3的mRNA表达。结果显示,NAC可以减轻GI/R损伤大鼠胃黏膜细胞的凋亡;促进大鼠I/R损伤的胃黏膜组织中p-ERK蛋白的表达,抑制p-JNK和NF-κB的蛋白表达,同时也抑制TNF-α mRNA和Caspase-3 mRNA的表达。股静脉给予辣椒素受体(vanilloid receptor subtype1,VR1)拮抗剂(capsaizepin,CPZ)400mg/kg,能逆转NAC对大鼠GI/R损伤的保护作用。以上结果提示:NAC对大鼠GI/R损伤具有减轻作用,其保护机制可能是通过上调胃黏膜组织中p-ERK,下调p-JNK和NF-κB实现的,且这种保护作用可能与VR1有关。     

吸入一氧化碳抗肢体缺血/再灌注损伤的实验研究

目的：观察吸入适量一氧化碳（CO）对大鼠肢体缺血/再灌注（I/R）损伤的防治作用。方法：SD大鼠44只,随机分为假手术（S）、I/R、I/R吸入CO（RC）组;通过夹闭股动脉4h、再开放48h,复制肢体I/R损伤模型;RC组行再灌注时,使动物吸入含有CO的医用空气（CO的体积分数为0.05%）,其余两组呼吸正常空气;对比观测缺血肢体大体及骨骼肌组织病理学、缺血肢体湿干重比值（W/D）的变化,流式细胞仪检测肌组织中Bax、Bcl-2的表达水平及细胞凋亡百分比,全自动生化分析仪检测血清乳酸脱氢酶（LDH）和肌酸激酶（CK）的变化。结果：与I/R组比较,RC组动物W/D、血清LDH及CK含量、肌组织中Bax表达水平及细胞凋亡百分比均显著降低,肌组织Bcl-2表达水平显著升高,缺血肢体大体观及肌组织病理学明显改善。结论：吸入适量浓度的外源性CO对肢体I/R损伤有防治作用。     

细胞自噬在大鼠缺血/再灌注肺损伤中的调控作用

目的: 探讨细胞自噬在大鼠缺血/再灌注肺损伤中的作用。方法: 随机将40只SD大鼠分为5组(n=8),分别为 ① 假手术组(Sham组):只开胸3.5 h;② 缺血/再灌注组(I/R组):开胸夹闭肺门缺血0.5 h后再灌注3 h;③ 溶剂组(DMSO组):术前1 h腹腔注射DMSO溶液;④自噬激动剂组(Rap组):术前腹腔注射雷帕霉素溶液;⑤自噬抑制剂组(3-MA组):术前1 h腹腔注射3-MA溶液;后三组的其余操作同I/R组。实验结束后处死大鼠,取肺组织,记录并计算肺组织湿/干重比(W/D)、总肺含水量变化(TLW) ,光镜和电镜观察肺组织及细胞形态,计算肺泡损伤率(IAR),Western blot检测自噬相关蛋白的表达情况。结果: 相对于sham组,其余四组肺W/D、TLW、IAR均明显升高,自噬相关蛋白表达明显上升,p-AMPK、Beclin 1、LC3 II 蛋白明显增多,p-mTOR、p62蛋白明显减少(P＜0.05或P＜0.01),光镜下其余各组肺组织有不同程度的水肿渗出,肺泡结构紊乱,电镜下细胞超微结构损伤加重,部分可见自噬小体;与DMSO组相比,3-MA组肺W/D、TLW、IAR明显下降(P＜0.05或P＜0.01),自噬相关蛋白表达明显下降,肺间质水肿较轻,细胞渗出较少,细胞超微结构损伤减轻,未见自噬小体。而I/R、DMSO、Rap组的各项指标变化无统计学差异(P＞0.05)。结论: 肺缺血/再灌注可诱发细胞自噬增强,从而引起大鼠肺损伤。