脂氧素A4后处理对大鼠全脑缺血再灌注时细胞凋亡的影响

目的 评价脂氧素A4时处理对大鼠全脑缺血再灌注时细胞凋亡的影响.方法 雄性成年SD大鼠180只,体重200 ～ 250 g,采用随机数字表法,将其分为3组:假手术组(S组)、缺血再灌注组(I/R组)和脂氧素A4后处理组(L组).I/R组和L组采用四血管阻塞法建立大鼠全脑缺血再灌注损伤模型.L组于再灌注即刻侧脑室注射脂氧素A4 100 ng(用生理盐水稀释至5ul),S组和I/R组侧脑室注射生理盐水5ul.分别于再灌注2、6、12、24和72 h时,处死6只大鼠,取脑组织,行HE染色,光镜下观察病理学结果,采用免疫组化法测定海马CA1区caspase-3表达.分别于再灌注2、6、12、24和72 h时,处死6只大鼠,取海马组织,采用流式细胞仪检测细胞凋亡率.结果 与S组比较,I/R组和L组再灌注各时点海马CA1区caspase-3表达上调,海马组织细胞凋亡率升高(P＜0.01);与I/R组比较,L组再灌注各时点海马CA1区caspase-3表达下调,海马组织细胞凋亡率降低(P＜0.01),病理学损伤减轻.结论脂氧素A4后处理减轻大鼠全脑缺血再灌注损伤的机制与下调caspase-3表达,减少细胞凋亡有关.     

芬太尼联合七氟烷后处理对离体大鼠缺血/再灌注心功能的影响

目的 研究芬太尼联合七氟烷后处理对离体大鼠缺血/再灌注(ischemia/reperfusion,I/R)心脏心功能的影响.方法 建立离体大鼠心脏缺血40 min,再灌注120 min模型.根据再灌注开始10 min的不同处理,使用随机数字表法将实验动物随机分为4组(n=10):I/R对照组(Con),七氟烷后处理组(...     

缺血后适应促进树鼩血栓性脑缺血时紧密连接occludin/ZO-1蛋白表达及抑制脑水肿的机制

 目的: 研究脑缺血及缺血后适应(postconditioning,PC)条件下,树鼩脑缺血时局部脑血流(regional cerebral blood flow,rCBF)、脑水肿及紧密连接(tight junction,TJ)的occludin和zonula occludins(ZO)-1蛋白表达的改变;探讨TJ表达对脑水肿及脑梗死的影响及其可能机制。方法: 将72只健康成年树鼩随机分为对照组、脑缺血组和脑缺血+PC组,其余3只动物用于磁共振成像(MRI)观察。通过光化学反应诱导树鼩局部血栓形成;缺血PC组于缺血后4 h夹闭患侧颈总动脉3次(每次5 min)实施PC处理。用电镜观察神经超微结构,用TUNEL法检测海马神经元的凋亡数量,用激光多普勒血流监测仪检测缺血区的rCBF,用免疫组化及Western blot法观察缺血海马occludin/ZO-1蛋白的表达,MRI技术监测脑梗死体积,组织干湿法检测脑含水量的改变。结果: 树鼩脑缺血后海马CA1区的正常神经元明显减少以及神经元超微结构明显异常。脑缺血组TUNEL阳性细胞数明显增加(P<0.01),rCBF明显降低,occludin/ZO-1表达减弱(P<0.01),脑含水量和脑梗死体积明显增加(P<0.01)。经PC处理的动物,缺血区rCBF增加,TJ表达增强,脑含水量降低,且TUNEL阳性细胞数和脑梗死体积明显减小(P<0.01)。结论: 缺血PC可增加树鼩缺血区rCBF但不增加局部含水量;提示缺血PC缩小脑梗死体积可能与occludin/ZO-1表达增强而抑制脑水肿有关。     

缺血后处理对在体大鼠缺血-再灌注心肌细胞色素P450表氧化酶2J3／环氧二十碳三烯酸系统的影响

目的观察缺血后处理拈抗心肌缺血-再灌注损伤时内源性细胞色素P450表氧化酶2J3／环氧二十碳三烯酸（CYP2J3／EET）系统的变化。方法复制在体大鼠心肌缺血-再灌注损伤及缺血后处理模型。雄性Wistar大鼠（250—300）g随机分为三组：假手术组（Sham）、缺血-再灌注组（I—R）、缺血后处理组（IPo）。动脉插管测定心功能指标,采用TTC染色法测定心肌梗死范围,采用RT—PCR法检测心脏细胞色素P450表氧化酶亚型2J3（CYP2J3）mRNA表达,采用Western blot方法测定心肌组织CYP2J3蛋白水平的变化,高效液相色谱法测定11,12-EET含量。结果与I-R组相比IPo组左室收缩末压（LVESP）、左室内压最大上升／下降速率（±LVdp／dtmax）均显著升高;心肌梗死面积减少20．76％（P〈0．01）;与Sham组及I—R组相比IPo组CYP2J3mRNA、CYP2J3蛋白及11,12-EET含量明显升高（P〈0．05）。结论[Po可减轻在体心肌I—R损伤同时上调心脏CYP2J3／EET系统;提示CYP2J3／EET系统可能与IPo拮抗心脏I-R损伤作用相关。     

吗啡后处理抗心肌缺血再灌注损伤心肌细胞凋亡中的作用及机制

目的探讨吗啡后处理抑制心肌缺血／再灌注损伤大鼠心肌细胞凋亡的作用以及对信号通路P13K／AKT的影响。方法采用麻醉开胸大鼠在体心脏缺血模型。SD大鼠56只随机分成4组,每组14只：S组（假手术,只穿线,不结扎）,I／R组（单纯缺血再灌注）,M组（吗啡后处理＋缺血再灌注,再灌注前3min和再灌注后2min内静脉注入吗啡1．25mg／kg）,W＋M组（wortmannin＋吗啡后处理＋缺血再灌注,左冠状动脉前降支结扎前20min静脉注入15ug／kgwortmannin,特异性的P13K阻断剂）。除S组外,所有大鼠心脏都经历45min缺血和120min再灌注。再灌注120min时,各组随机取9只大鼠,TUNEL染色检测心肌细胞凋亡。其余5只大鼠采用Western Blot法测定心肌组织总AKT和磷酸化AKT的表达水平。结果再灌注120min,可在I／R组缺血区心肌检测到大量凋亡心肌细胞183=1．14％,吗啡后处理显著降低心肌细胞凋亡指数（10．83=1．24％,P〈0．01）;吗啡后处理使磷酸化AKT的蛋白表达明显增加。特异性的P13K阻断剂,wortmannin完全消除了吗啡后处理抑制缺血／再灌注损伤大鼠心肌细胞凋亡的作用,及抑制磷酸化AKT蛋白表达的增加。结论大鼠在体心脏缺血模型,吗啡后处理可通过P13K／AKT信号通路,抑制心肌缺血／再灌注损伤心肌细胞凋亡。     

川芎嗪后处理对大鼠心肌缺血再灌注损伤的保护作用

目的：观察川芎嗪后处理对大鼠心肌缺血再灌注损伤的保护作用及探讨其可能的作用机制。方法：采用结扎大鼠左冠状动脉前降支方法制备心肌缺血再灌注损伤模型,记录各组心律失常发生情况,测定肌酸激酶（CK）、超氧化物歧化酶（SOD）、丙二醛（MDA）、一氧化氮（NO）、一氧化氮合酶（NOS）含量,HE染色光镜下观察心肌组织形态学改变并秤重检测心肌梗死面积。结果：川芎嗪组的心律失常发生率明显降低,心肌细胞肿胀明显减轻,血中SoD、NO、NOS含量增加,MDA,CK的生成减少。（P〈0．05）。结论：川芎嗪后处理能降低心律失常发生、减少坏死面积,其作用可能与提高sOD、NO、NOs含量,减少MDA生成有关。     

Postconditioning inhibits mPTP opening independent of oxidative phosphorylation and membrane potential

Mitochondrial permeability transition pore (mPTP) inhibition plays a relevant role in postconditioning (PostC). Ischemia damages the electron transport chain, and the potential contribution of additional modifications in mitochondrial function caused by PostC remains unknown. We sought to determine which mitochondrial functions are involved in the inhibition of mPTP opening during the first minutes of reperfusion. Anesthetized New Zealand White rabbits underwent 30-min ischemia followed by 10-min reperfusion. At reperfusion, they received either no intervention (Control, C), PostC with 4 cycles of 1-min ischemia followed by 1-min reperfusion, or an IV injection of 5 mg/kg cyclosporine A (CsA: a powerful inhibitor of mPTP opening). Sham rabbits underwent no ischemia throughout the 40-min experiment. At the end of the 10-min reperfusion, mitochondria were isolated from the area at risk by differential centrifugations. Calcium retention capacity (CRC) and mitochondrial membrane potential (ΔΨ_m) were assessed by fluorimetry in subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria. Oxidative phosphorylation was assessed using a Clark-type electrode, and oxidative stress via protein carbonylation by Western blotting. PostC and CsA treatments improved CRC when compared to the C group. Control, PostC and CsA mitochondria exhibited a comparable significant dissipation of ΔΨ_m, together with a comparable significant decrease in state 3 and an increase in state 4 respiration, in both SSM and IFM. However, PostC but not CsA treatment reduced total heart oxidative stress. These data suggest that during the early minutes of reperfusion, PostC reduces oxidative stress and inhibits mPTP opening, independent of alteration of oxidative phosphorylation or of ΔΨ_m.     

舒芬太尼后处理对二尖瓣置换患者心肌缺血/再灌注损伤的影响

目的 评价主动脉根部灌注舒芬太尼对体外循环(cardiopulmonary bypass,CPB)下二尖瓣置换患者心肌缺血/再灌注(ischemia/reperfusion,I/R)损伤的影响.方法 择期拟行二尖瓣置换术的风湿性心脏病患者60例,年龄18岁～65岁,美国麻醉医师协会(ASA)分级Ⅱ或Ⅲ级,心功能分级I或Ⅱ级,采用随机数字表法分为2组(每组30例):舒芬太尼后处理组(S组)和对照组(C组).S组在主动脉开放前5 min经主动脉根部一次性给予舒芬太尼0.2 μg/kg,C组给予同等容积的生理盐水.于麻醉诱导前(基础状态),主动脉开放后4、8、24 h和48 h,采集右颈内静脉血样,测定心肌肌钙蛋白Ⅰ(cardiac troponin Ⅰ,cTnⅠ)的浓度和肌酸激酶同工酶(creatine kinase-MB,CK-MB)的活性.记录两组患者血流动力学变化及术后呼吸机辅助时间、重症监护室(intensive care unit,ICU)停留时间、术后住院时间以及术后24 h心肌收缩评分等指标.结果 两组患者的平均动脉压(mean artery pressure,MAP)、心率(heart rate,HR)、中心静脉压(central venous pressure,CVP)、心排血量(cardiac output,CO)和每搏量(stroke volume,Sv)比较,差异无统计学意义(P＞0.05).S组主动脉开放后4、8h时cTnⅠ [(0.50±0.09)、(0.39±0.08) μg/L]浓度及CK-MB[(63±7)、(61±7) U/L]活性较C组[(0.70±0.11)、(0.50±0.10) μg/L,(83±10)、(75±7) U/L]明显降低(P＜0.05).S组术后呼吸辅助时间[(12±4)h]、ICU停留时间[(34±11) h]和术后住院时间[(10±3)d]较C组[(14±4)h、(44±14)h、(13±4)d]明显缩短(P＜0.05),且术后24 h心肌收缩评分[(7.6±2.8)μg·kg-1·min-1]也较C组[(10.3±3.9) μg· kg-1· min-1]明显降低(P＜0.05).结论 主动脉根部灌注舒芬太尼可减轻CPB下二尖瓣置换患者心肌I/R损伤,其机制有待进一步探讨.     

Effect of remote ischemic postconditioning in inflammatory changes of the lung parenchyma of rats submitted to ischemia and reperfusion

Objective

To assess the effects of postconditioning remote in ischemia-reperfusion injury in rat lungs.

Methods

Wistar rats (n=24) divided into 3 groups: GA (I/R) n=8, GB (R-Po) n=8, CG (control) n=8, underwent ischemia for 30 minutes artery occlusion abdominal aorta, followed by reperfusion for 60 minutes. Resected lungs and performed histological analysis and classification of morphological findings in accordance with the degree of tissue injury. Statistical analysis of the mean rating of the degree of tissue injury.

Results

GA (3.6), GB (1.3) and CG (1.0). (GA GB X P<0.05).

Conclusion

The remote postconditioning was able to minimize the inflammatory lesion of the lung parenchyma of rats undergoing ischemia and reperfusion process.