阿片受体在异氟醚延迟预处理减轻兔心肌缺血再灌注损伤中的作用

Objective To investigate the role of opioid receptors in the protective effects of isoflurane-induced delayed preconditioning against myocardial ischemia-reperfusion (I/R) injury in rabbits. Methods Forty male New Zealand white rabbits weighing 2.0-2.5 kg were randomly assigned into 4 groups ( n = 10 each) : group I sham operation (S); group II I/R; group Ⅲ isoflurane + I/R (Iso) and group IV Iso + naloxone + I/R (Nal). Myocardial I/R was induced by 40 min occlusion of left anterior descending branch (LAD) of coronary artery followed by 120 min reperfusion. In group Ⅲ (Iso) 2% isoflurane in 100% O2 was inhaled for 2 h and I/R was produced 24 h later. In group IV (Nal) naloxone 6 mg/kg was given iv 10 min before 2 h of 2% isoflurane inhalation and I/R was produced 24 h later. At the end of 120 min reperfusion, infarct size (IS) and area at risk (AAR) were determined by Evan's blue and TTC staining. Myocardial ultrastructure was examined by electron microscopy. The phosphorylated p38MAPK protein expression in myocardium was determined by Western blot. Results The IS was significantly smaller in group Iso ( Ⅲ ) ( 19.7% ± 2.8%) than in I/R group ( II ) (37.8% ±1.7%) (P<0.05). The phosphorylated p38MAPK protein expression in myocardium was significantly lower in group Iso than in group I/R. Microscopic examination showed less myocardial damage in Iso group than in group I/R. The protective effects of delayed preconditioning by isoflurane was prevented by naloxone pretreatment. ConclusionOpioid receptors may be involved in the protective effects of delayed preconditioning by isoflurane against myocardial I/R injury.     

硫化氢延迟预处理抑制大鼠心肌损伤的机制研究

[目的]探讨硫化氢预处理对大鼠心肌缺血再灌注损伤的保护机制.[方法]健康成年S-D雄性大鼠30只,随机分成三组,每组10只.假手术组(S组)仅开胸并分离冠状动脉左前降支,但不阻断血流;缺血再灌注组(IR组)行冠状动脉左前降支阻断30 min,再灌注120 min;硫化氢组(H组)予以静脉注射硫氢化钠0.05 mg/kg,给药后24 h同IR组处理.再灌注结束后检测血清IL-6和IL-10水平,免疫印迹法检测心肌过氧化物酶体增殖物激活受体γ(PPAR-γ)水平并比较.[结果]与S组比较,IR组和H组在缺血再灌注后血清IL-6和IL-10水平升高(P＜0.05);但与IR组比较,H组IL-10水平升高,IL-6水平下降(P＜0.05);与S组比较,IR组和H组PPAR-γ表达下降(P＜0.05);但与IR组比较,H组PPAR-γ表达升高(P＜0.05).[结论]硫化氢预处理抑制大鼠心肌损伤的保护作用,可能与促进心肌PPAR-γ表达有关.     

异氟醚延迟相预处理对兔心肌缺血-再灌注损伤的保护作用

目的探讨异氟醚延迟相预处理对兔心肌缺血-再灌注损伤的保护及对炎性细胞因子的影响。方法30只健康新西兰雄性大白兔随机均分成三组:缺血-再灌注组(I/R组)、2.0%异氟醚延迟相预处理组(S组)、假手术组(C组)。I/R组吸入100%氧气2h,24h后行左冠状动脉前降支阻断40min,再灌注120min;S组吸入2.0%异氟醚 100%氧气2h,24h后处理同I/R组;C组吸入100%氧气2h,24h后仅行左冠脉套线而不阻断160min,各组分别于阻断前20min(T1)、阻断后20min(T2)、40min(T3)、再灌注1h(T4)、2h(T5)五个时点取颈内动脉血测定血清中肌钙蛋白(cTnI)、白细胞介素10(IL-10)和肿瘤坏死因子α(TNF-α)含量。再灌注结束后观察心肌细胞超微结构的变化,用伊文思蓝和TTC染色法测心肌梗死面积。结果与C组比,I/R组与S组cTnI、IL-10和TNF-α含量均升高(P<0.05),但与I/R组比,S组IL-10明显升高(P<0.05),心肌梗死面积减少(P<0.05),cTnI和TNF-α明显降低(P<0.05)。结论异氟醚延迟相预处理通过调控炎性细胞因子平衡发挥心肌保护作用。     

异氟醚预处理延迟相对兔缺血再灌注心肌TNF-α水平及Caspase-3蛋白表达的影响

目的 探讨异氟醚预处理延迟相对缺血再灌注心肌的保护作用及其机制.方法 30只健康新西兰雄性大白兔随机分成3组:假手术组(C组)、缺血再灌注组(I/R组)、2.0%异氟醚预处理组(S组),每组10只.C组仅开胸160 min,I/R组行左冠脉阻断40 min,再灌注120 min,S组吸入2.0%异氟醚2 h,24 h后处理同I/R组.各组分别于左冠脉阻断前20 min(T1)、左冠脉阻断20 min(T2)、左冠脉阻断40 min(T3)、再灌注1 h(T4)、再灌注2 h(T5)五个时点抽取血测血清TNF-α水平.再灌注结束后免疫印记法测心肌Caspase-3蛋白表达水平,用伊文思蓝和TTC染色测心肌梗死面积.结果 与I/R组比,S组TNF-α水平降低(P＜0.05),Caspase-3表达降低(P＜0.05),心肌梗死面积减少(P＜0.05).结论 异氟醚预处理延迟相通过下调心肌Caspase-3表达和TNF-α生成来减轻缺血再灌注损伤发挥保护作用.     

异氟醚预处理延迟相对兔心肌缺血-再灌注损伤核因子-κB的影响

目的 探讨异氟醚预处理延迟相对心肌缺血-再灌注损伤的保护机制.方法 雄性新西兰兔30只,体质量2.0～2.5 ks.随机分成3组(n=10):假手术组(C组)、缺血再灌注组(I/R组)、2.0%异氟醚预处理组(S组).C组吸入100%氧气2 h,24 h后仅行左冠脉套线而不阻断160 min,I/R组吸入100%氧气2 h,24 h后行左冠状动脉前降支阻断40 min,再灌注120 min;S组吸入2.0%异氟醚+100%氧气2 h,24 h后处理同I/R组.各组分别于左冠前降支阻断前20 min(TI)、左冠前降支阻断20 min(T2)、左冠前降支阻断40 min(T3)、心肌再灌注1 h(T4)、心肌冉灌注2 h(T5)五个时点抽取颈内动脉血ELISA法测血清IL-10和TNF-α水平.再灌注结束后观察心肌细胞超微结构的变化,免疫印记法测心肌核因子-κB(NF-κB)活性水平,同时用伊文思蓝和TTC染色法测心梗面积.计量资料采用均数±标准差(x±s)表示,用SPSS 13.0统计学软件进行分析,组间采用方差分析,以P<0.05为差异具有统计学意义.结果 与I/R组比,S组IL-10明显升高(P<0.05),TNF-α明显降低(P<0.05),NF-κB表达降低(P<0.05),心肌梗死面积减少(P<0.05).结论 异氟醚预处理延迟相通过抑制心肌NF-κB的活性,调控炎性细胞因子平衡来减轻心肌缺血-再灌注损伤发挥保护作用.     

mitoK(ATP)介导硫化氢预处理延迟相的心肌保护效应

目的:研究线粒体ATP敏感性钾通道[mitoK(ATP)]激活在硫化氢预处理延迟相对大鼠心肌细胞的保护效应。方法:将32只健康成年雄性SD大鼠随机分成假手术组(Sham组)、缺血再灌注组(IR组)、硫化氢预处理组(HS组)和5-羟葵酸(5-HD)+硫化氢预处理组(HD组),每组8只。Sham组仅穿线但不阻断左冠状动脉前降支(LAD);IR组结扎LAD30min,松解后再灌注120min;HS组静脉注射硫化氢供体NaHS50μg/kg,24h后同IR组处理;HD组于结扎前15min静脉注射5-HD5mg/kg,其他同HS组处理。检测心室面积、心肌缺血面积和梗死面积,计算缺血和梗死面积百分比;电镜下观察心肌细胞超微结构。结果:3组缺血面积百分比差别无统计学意义(P>0.05);HS组心肌梗死面积百分比低于IR组和HD组(P<0.01或P<0.05),HD组与IR组相比差异无统计学意义(P>0.05)。心肌细胞超微结构损伤程度HS组较IR组明显减轻,而HD组与IR组差异不大。结论:硫化氢预处理延迟相可保护缺血再灌注损伤的心肌,mitoK(ATP)介导了硫化氢预处理延迟相的心肌保护通路。     

腺苷A1受体激动剂延迟预处理对缺血再灌注兔心肌炎性细胞因子的影响

目的 探讨腺苷A1受体激动剂(2-氯环戊腺苷,CCPA)延迟预处理对兔心肌缺血再灌注损伤的保护机制及对炎性细胞因子的影响.方法 30只健康新西兰雄性大白兔随机分成3组:假手术组(C组)、缺血再灌注组(I/R组)、CCPA组(P组),每组10只.C组仅行左冠脉套线而不阻断160 min,I/R组行左冠脉阻断40min,再灌注120 min,P组在静注CCPA 0.1 mg/kg 24h后,处理同I/R组.各组分别于左冠前降支阻断前20min(T1)、左冠前降支阻断20 min(T2)、左冠前降支阻断40 min(T3)、心肌再灌注1 h(T4)心肌再灌注2 h(T5)5个时点抽取颈内动脉血测定血清中肌钙蛋白(cTnI)、白介素-10(IL-10)和白介素-6(IL-6)含量.再灌注结束后观察心肌细胞超微结构的变化,用伊文思蓝和TTC染色法测心梗面积.结果 与C组比,I/R组与P组cTnI、IL-10和IL-6含量均增高(P<0.05),但与I/R.组比,P组IL-10增高(P<0.05),心肌梗死面积减少(P<0.05),cTnl和IL-6降低(P<0.05).结论 腺苷A1受体激动剂延迟预处理通过调控炎性细胞因子平衡发挥心肌保护作用.     

腺苷A_1受体激动剂后处理对兔心肌缺血-再灌注损伤的影响

目的 探讨腺苷A1受体激动剂(2-氯环戊腺苷,CCPA)后处理对兔心肌缺血-再灌注损伤的保护作用.方法 32只兔随机均分为四组:假手术组(S组,开胸后仅行左冠状动脉套线而不阻断160min)、缺血-再灌注组(IR组,行左冠状动脉前降支阻断40 min,再灌注120 min)、缺血后处理组(lPC组,结扎左冠状动脉前降支40 min,再通30 s,结扎30 s,重复3次,再灌注120 min)和CCPA后处理组(APC组,结扎左冠状动脉前降支40 min,开放左冠状动脉1 min内予以静推CCPA100 μg/kg,冉灌注120 min).分别于左冠状动脉前降支阻断前20 min(T1)、左冠状动脉前降支阻断20 min(T2)、左冠状动脉前降支阻断40 min(T3)、心肌再灌注1 h(T4)和心肌再灌注2 h(T5)抽取颈内动脉血测定血清心肌肌钙蛋白I(cTnI)含量.再灌注末抽血离心测定超氧化物歧化酶(SOD)、丙二醛(MDA),测定心肌梗死面积.结果 和IR组相比,IPC组和APC组再灌注各个时间点cTnI均降低(P<0.05);IPC组和APC组梗死面积均小于IR组(P<0.05);IPC组和APC组血清中sOD的活性高于IR组,MDA的含量低于IR组(P<0.05).结论 腺苷A1受体激动剂后处理具有类似缺血后处理的心肌保护作用.其机制可能是通过减少氧自山基的生成,增强心肌抗氧化能力.     

异氟烷预处理对心脏换瓣术患者血MMP-9的影响及其对心肌的保护作用

目的:观察异氟烷预处理对体外循环(cardiopulmonary bypass,CPB)心脏换瓣术患者围术期血浆基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)及心肌超微结构的影响,评价其对心肌的保护作用.方法:择期CPB下行瓣膜置换术的心脏瓣膜病患者30例,随机分为异氟烷预处理组(异氟烷组,n＝15)和对照组(n＝15),异氟烷组在麻醉诱导后CPB前吸入1.1%～1.2%(呼气末浓度)的异氟烷30 min,洗脱15 min,对照组不吸入异氟烷,其余用药两组无区别.分别于切皮前(T0),主动脉开放30 min(T1),6 h(T2),12 h(T3)及24 h(T4)经桡动脉取血测血浆MMP-9浓度,分别于CPB前后取部分右心耳组织电镜下观察超微结构.结果:与T0比较,对照组血浆MMP-9浓度在T1-T3显著增加,异氟烷组血浆MMP-9浓度只在T1显著升高(P<0.01);与对照组比较,异氟烷组血浆MMP-9浓度在T2显著降低(P<0.01),在T1-T3各时点与T0的差值均显著降低(P<0.01).电镜下可见对照组CPB后心肌细胞损伤比异氟烷组严重.结论:异氟烷预处理能显著抑制心脏换瓣术患者CPB后MMP-9的分泌增多,这可能是其对心脏换瓣术患者心肌保护的机制之一.     

阿片受体在异氟醚延迟预处理减轻兔心肌缺血再灌注损伤中的作用

Objective To investigate the role of opioid receptors in the protective effects of isoflurane-induced delayed preconditioning against myocardial ischemia-reperfusion (I/R) injury in rabbits. Methods Forty male New Zealand white rabbits weighing 2.0-2.5 kg were randomly assigned into 4 groups ( n = 10 each) : group I sham operation (S); group II I/R; group Ⅲ isoflurane + I/R (Iso) and group IV Iso + naloxone + I/R (Nal). Myocardial I/R was induced by 40 min occlusion of left anterior descending branch (LAD) of coronary artery followed by 120 min reperfusion. In group Ⅲ (Iso) 2% isoflurane in 100% O2 was inhaled for 2 h and I/R was produced 24 h later. In group IV (Nal) naloxone 6 mg/kg was given iv 10 min before 2 h of 2% isoflurane inhalation and I/R was produced 24 h later. At the end of 120 min reperfusion, infarct size (IS) and area at risk (AAR) were determined by Evan's blue and TTC staining. Myocardial ultrastructure was examined by electron microscopy. The phosphorylated p38MAPK protein expression in myocardium was determined by Western blot. Results The IS was significantly smaller in group Iso ( Ⅲ ) ( 19.7% ± 2.8%) than in I/R group ( II ) (37.8% ±1.7%) (P<0.05). The phosphorylated p38MAPK protein expression in myocardium was significantly lower in group Iso than in group I/R. Microscopic examination showed less myocardial damage in Iso group than in group I/R. The protective effects of delayed preconditioning by isoflurane was prevented by naloxone pretreatment. ConclusionOpioid receptors may be involved in the protective effects of delayed preconditioning by isoflurane against myocardial I/R injury.