无创肢体缺血预处理联合后处理对心肌缺血/再灌注损伤的影响

目的 探讨无创肢体缺血预处理(NILIPC)和后处理(NILIPostC)联合应用对体外循环心脏手术中心肌缺血/再灌注损伤的保护作用.方法 60例风湿性心脏病拟行机械瓣膜置换者随机分为实验1、2、3组和对照组.实验1组在主动脉阻断前10 min右下肢实施NILIPC;实验2组在主动脉开放前10 min右下肢实施NILI...     

Rho激酶在远距缺血后处理抗心肌缺血/再灌注损伤中的作用

目的探讨Rho激酶在远距缺血后处理(remote ischemic postconditioning,RIPost C)中的作用及其可能的作用机制。方法 30只♂SD大鼠随机分为假手术组(Sham)、缺血/再灌注组(I/R)、远距缺血后处理组(RIPost C)、缺血/再灌注+Rho激酶阻断剂法舒地尔组(I/R+Fas),远距缺血后处理+Rho激酶激动剂溶血磷脂酸组(RIPost C+LPA),每组6只。全程监测动脉血压和Ⅱ导联心电图,实验结束后测定血浆肌酸激酶(CK)、乳酸脱氢酶(LDH)活性变化,HE染色观察心肌组织形态学变化,TTC染色法评价心肌梗死面积,Western blot测定磷酸化肌球蛋白轻链(p-MLC)蛋白表达。结果与Sham组相比,其余各组MAP、HR均下降,ST段增高;与I/R组相比,RIPost C和I/R+Fas组MAP、HR升高,ST段降低,心肌组织病理形态有明显改善,炎性细胞浸润减轻,心肌梗死面积降低,CK、LDH释放减少,p-MLC表达降低;与RIPost C组相比,RIPost C+LPA组减弱了RIPost C的作用,抑制了上述指标的恢复。结论 Rho激酶信号通路可能参与了远距缺血后处理抗心肌缺血/再灌注损伤的作用。     

重组人脑利钠肽后适应对兔急性缺血再灌注损伤心肌的保护作用

目的探讨重组人脑利钠肽（rhBNP）后适应对兔急性缺血／再灌注（I／R）心肌的保护作用及其机制。方法将36只健康日本大耳白兔按数字表法随机分为三组（每组12只）,即假手术组、I／R组（缺血40rain后再灌注180min）及BNP＋I／R组（I／R前5min以0．01μg／kg静脉给予rhBNP）。假手术组开胸于左冠回旋支只穿线但不结扎,观察180min结束;I／R组及BNP＋I／R组：缺血40min,分别再灌注180min后处死。进行心肌磷酸肌酸激同工酶（CK．MB）含量检测,观察心肌HE染色后病理形态变化及BCI-2、Bax表达的检测。结果与假手术组相比,I／R组和BNP＋I／R组CK—MB水平均显著增高（t=3．047、3．032,均P〈0．01）;与I／R组相比,BNP＋I／R组心肌酶明显升高（t=3．067,P〈0．01）。与假手术组相比,I／R组及BNP＋L／R组均可见到凋亡细胞,但BNP＋IYR组凋亡细胞明显减少,UR组Bax的表达增加,Bcl-2的表达降低。与I／R组相比,BNP＋I／R组Bax的表达明显升高,而Bcl-2的表达明显降低。结论rhBNP可减少梗死后心肌的损伤;可以增加梗死后心肌细胞抑制凋亡基因（Bcl-2）的表达,从而减少心肌细胞的凋亡。     

无创性肢体缺血预适应对大鼠心肌缺血/再灌损伤后纤溶因子的影响

目的观察无创性肢体缺血预适应(NLIP)对心脏缺血/再灌损伤后纤溶因子的影响,进一步探讨其对心脏的延迟保护作用。方法连续3d,每天1次,3个循环下肢无创性5min缺血,5min再灌建立NLIP模型。实验分3组:模型组(I/R);心脏缺血预适应组(CIP);NLIP组。再灌末取心肌组织,以四氮唑染色法测定心肌梗死面积(IS/AAR×100%)。取血,以发色底物法测定血浆中t-PA和PAI-1活性,以羟胺法测定血浆中SOD活性。结果与I/R组(44.5±8.1)%比较,CIP和NLIP能明显降低梗死面积(28.6%±9.5%和25.4%±8.7%,P<0.01);与I/R组t-PA(1.01±0.33)U·ml-1和PAI-1(27.11±0.63)AU·ml-1比较,CIP和NLIP均能明显对抗血t-PA活性的降低〔(1.98±0.46)和(1.89±0.44)U·ml-1,P<0.01〕和PAI-1活性的升高〔(25.42±0.56)和(22.01±0.45)AU·ml-1,P<0.01〕;与I/R组(300±49)NU·ml-1比较,CIP和NLIP均能明显提高再灌后SOD活性〔(366±72)和(388±67)NU·ml-1,P<0.05和P<0.01〕。结论NLIP对心肌缺血/再灌损伤具有保护作用,机制可能与其对纤溶系统的影响有关。     

七氟醚预处理通过升高血浆脂联素水平保护心肌缺血/再灌注损伤

目的探讨脂联素是否参与七氟醚预处理对心肌缺血/再灌注(myocardial ischemia-reperfusion,MI/R)损伤的保护作用。方法将C57小鼠随机分为4组,每组10只:Sham-Control(假手术组)、MI/R-control(模型组)、MI/R-Sevopre(预处理组)、APN-KO-MI/R-Sevopre(敲基因预处理组),MI/R造模术后24 h检测各组小鼠血浆脂联素水平;检测各组小鼠24 h左心室收缩末期内径,舒张末期内径以及射血分数;Tunel染色观察各组心肌细胞形态和凋亡情况;伊文思蓝-TTC染色观察心梗面积。结果相比于假手术组,模型组心功能受损,射血分数降低,舒张末期内径以及收缩末期内径增加,同时,模型组心肌梗死面积显著增加,凋亡细胞增多,并且血浆脂连素水平降低;相比于模型组,七氟醚预处理组小鼠心功能改善,心肌梗死面积降低,凋亡细胞减少,血浆脂连素水平升高;敲基因预处理组小鼠相比于预处理组,七氟醚预处理改善MI/R损伤作用降低。结论七氟醚预处理通过升高血浆脂连素水平保护MI/R损伤。     

脑利钠肽后处理对高血脂大鼠缺血／再灌注心肌的保护作用

目的观察脑利钠肽后处理对高血脂大鼠缺血／再灌注心肌的保护作用。方法高血脂SD大鼠24只,随机分为3组：假手术组、缺血／再灌注组、脑利钠肽后处理组,每组8只。制备大鼠心肌缺血／再灌注模型。测定血清肌酸激酶（CK）、超氧化物岐化酶（SOD）、丙二醛（MDA）含量和心肌梗死范围。结果再灌注结束后,脑利钠肽后处理组和缺血／再灌注组CK明显高于假手术组[分别为（758．11±39．94）,（815．19±40．85）,（219．17±22．63）U／L,P〈0．01],脑利钠肽后处理组CK低于缺血／再灌注组（P〈0．05）。脑利钠肽后处理组血清中SOD含量高于缺血／再灌注组,MDA含量低于缺血／再灌注组（P〈0．05）。脑利钠肽后处理组坏死区与缺血区比值低于缺血／再灌注组[分别为（33．0±5．2）％,（38．4±3．1）％,P〈0．05]。结论脑利钠肽后处理对高血脂大鼠缺血／再灌注心肌具有保护作用。     

远距后处理对心肌缺血/复灌损伤中线粒体渗透性转换及细胞凋亡的影响

目的研究远距后处理对大鼠心肌缺血/复灌损伤的保护作用,并探讨其对线粒体渗透性转换孔及细胞凋亡的影响。方法 60只♂Sprague-Dawley大鼠随机分成5组(n=12):假手术组(Sham)、缺血/复灌组(I/R)、远距后处理组(Rpost C)、远距后处理+Atr组(Rpost C+Atr)、缺血/复灌+Atr组(I/R+Atr)。所有组大鼠开胸后冠状动脉左前降支(LAD)下穿线。除Sham组之外,其余各组均LAD缺血45min复灌180 min。Rpost C组:LAD缺血15 min后,同时给予右侧股动脉结扎模拟缺血5 min,松开结扎线复灌5 min,重复循环3次;Rpost C+Atr组:同Rpost C组,并于复灌前30 s静脉注射线粒体渗透性转换孔开放剂苍术苷(Atr,5 mg.kg-1);I/R+Atr组:同I/R组,并于复灌前30 s静脉注射Atr。连续监测动脉血压和心率变化。实验结束后测定血浆乳酸脱氢酶(LDH)、磷酸肌酸激酶(CK)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性;检测心肌梗死面积;心肌组织细胞caspase-3的活性;RT-PCR测定左心室前壁心尖组织Bax、Bcl-2 mRNA表达。结果与I/R组相比,Rpost C组LDH、CK、MDA含量均降低,SOD活性增加,心肌梗死面积减小,caspase-3活性减弱,Bcl-2/Bax mRNA比值增高。线粒体渗透性转换孔开放剂Atr减弱Rpost C的作用。结论远距后处理对心肌缺血/复灌损伤有明显的保护作用,其机制可能与抑制线粒体渗透性转换孔的开放和抑制细胞凋亡有关。     

Ferilnic nirate produces delayed preconditioning against myocardial ischemia and reperfusion injury in rats

To determine whether ferilnic nirate (FLNT) can precondition the rat heart against myocardial ischemia/reperfusion (I/R) damage and its mechanism, two groups of experiments were conducted. In the first group of experiments, rats were divided among four treatment groups: sham group; solvent with I/R (I/R control group); FLNT pretreatment with I/R (I/R FLNT group); and late ischemic preconditioning group (LPC group). In the second group of experiments without I/R, rats were divided into two treatment groups: control group and FLNT group. The results indicated that myocardial infarct size and the levels of creatine kinase and lactate dehydrogenase in the sera of the I/R FLNT group were significantly lower and the level of nitric oxide molecule and Mn-containing superoxide dismutase were significantly elevated in the heart tissue compared with I/R control group. The protein expression ratio of Bcl-2/Bax in heart tissue was significantly elevated in the I/R FLNT group. These results demonstrate FLNT is able to precondition rat hearts against myocardial ischemia/reperfusion damage to a similar level as that achieved via the late phase of ischemic preconditioning. The mechanism may involve the up-regulation of nitric oxide and the strengthening of anti-oxidant and anti-apoptosis cellular functions.     

缺血后适应减轻急性下肢缺血再灌注损伤的实验研究

目的 观察缺血后适应(IPC)减轻急性下肢缺血(AU)再灌注损伤的疗效并探讨其机制.方法 将45只新西兰大白兔采用高脂饮食与动脉内膜球囊损伤结合的方式建立下肢动脉粥样硬化狭窄动物模型,随机分为对照组、缺血再灌注组(IR组)、缺血后适应组(IPC组),每组各15只.检测三组大白兔阻断股动脉前、持续再灌注2h后血液中肌酸激酶(CK)、丙二醛(MDA)、超氧化物岐化酶(SOD)水平,观察再灌注后下肢骨骼肌组织学改变,并采用原位末端标记法(TUNEL)分析三组大白兔下肢再灌注后骨骼肌细胞凋亡情况.结果 与IR组比较,IPC组兔血浆CK、MDA明显降低[(7.49±0.84) U/L与(8.19±1.06) U/L,P＜0.05],[(3.67±0.36) nmol/L与(4.06±0.55) nmol/L,P＜0.05],而SOD则显著升高[(420.40±30.94)μmol/L与(384.73±44.12) μmol/L,P＜0.05],骨骼肌细胞凋亡指数降低[(12.27±2.11)％与(16.62±1.44)％,P＜0.01],差异有统计学意义,并且组织形态学观察IPC组兔骨骼肌损伤、坏死程度较IR组减轻.结论 急性下肢缺血应用IPC能显著减轻下肢缺血再灌注损伤,其机制与减少自由基生成、增强抗氧化及减轻缺血再灌注诱导的骨骼肌细胞凋亡有关.     

精胺预处理对离体灌流大鼠心肌缺血/再灌注损伤及细胞凋亡的影响

目的探讨精胺预处理对离体灌流大鼠心肌缺血/再灌注损伤的影响及其可能的抗凋亡作用。方法应用Langehdorff离体灌流大鼠心脏复制模拟心肌缺血/再灌注损伤模型。24只大鼠随机分为3组,每组8只:对照组(Con-trol)、缺血/再灌注组(IR)、精胺干预组(Spermine)。比色法测定冠脉流出液中乳酸脱氢酶(LDH)活力,心肌组织中超氧化物歧化酶(SOD)活性及心肌丙二醛(MDA)含量;多导生理记录系统记录心脏功能;HE染色光镜下观察心肌形态学变化;三苯基氯化四氮唑(TTC)染色检测心肌梗死面积;透射电镜和TUNEL方法检测细胞凋亡;免疫组化检测心肌Fas与Bcl-2蛋白的表达。结果 (1)与对照组比,IR组冠脉LDH漏出明显增多、心肌组织中MDA水平增加、SOD活性降低(P<0.01);心功能明显下降(LVDP,HR,CF均低于对照组,P<0.05);光镜下可见心肌细胞呈凝固性或带状坏死。与Control组比,IR组心肌梗死面积及心肌细胞凋亡率明显增加(P<0.01);心肌Fas蛋白表达上调,Bcl-2蛋白表达下调。透射电镜下心肌细胞核染色质浓缩、凝聚且边集,染色质在核膜周边聚集形成新月形,线粒体嵴排列紊乱。(2)与IR组比,Spermine组冠脉LDH漏出减少,心肌组织中MDA减少,SOD增加(P<0.01);心功能有明显改善(LVDP,HR,CF均明显高于IR组,P<0.05);光镜下心肌细胞结构清晰。Spermine组与IR组比心肌梗死面积及心肌细胞凋亡率均明显降低(P<0.01);心肌Fas蛋白表达下调,Bcl-2蛋白表达上调;电镜下可见心肌肌节结构清晰,线粒体嵴完整、基质致密,未见核染色质凝聚。结论外源性精胺能明显减轻离体灌流大鼠心肌缺血/再灌注损伤,其机制可能与精胺抑制细胞凋亡有关。     

心肌缺血再灌注损伤动物模型建立的主要影响因素

心肌缺血再灌注损伤模型系模拟人心肌梗死及其再灌注治疗,研究缺血预适应机制,评价抗心肌缺血及心律失常药物疗效常用的动物模型。本文从冠状动脉血管结扎部位、进针深浅度和结扎松紧度等多个方面阐述了影响心肌缺血再灌注损伤实验动物模型建立的主要因素。     

辛伐他汀后处理对离体大鼠心肌缺血再灌注损伤的影响及机制

目的观察辛伐他汀对离体大鼠心肌缺血再灌注损伤(I/R)细胞凋亡的影响,初步探讨其机制。方法采用Langendorff离体心脏灌流模型,32只SD大鼠随机等分为4组:对照组、I/R组、辛伐他汀后处理组、辛伐他汀+L-硝基精氨酸甲酯(L-NAME)组。进行再灌注心律失常分析;冠脉流出液中肌酸激酶(CK)、乳酸脱氢酶(LDH)及NO含量测定;Western印迹法检测心肌组织p-Akt信号蛋白的表达;Annexin-V-FITC/PI法检测细胞凋亡指数(AI)。结果与I/R组比较,辛伐他汀后处理组心律失常发生率下降、CK和LDH含量降低、p-Akt蛋白表达及NO含量增加、细胞AI降低(P<0.01)。辛伐他汀+L-NAME组较辛伐他汀后处理组心律失常发生率升高、CK和LDH含量增加、p-Akt蛋白表达及NO含量降低、细胞AI增高(P<0.01);与I/R组比较,无显著差异(P>0.05)。结论辛伐他汀后处理能减轻大鼠心肌I/R损伤,减少心肌细胞凋亡,其作用机制可能与PI3K-Akt通路活化有关。     

七氟烷预处理对成年及幼年大鼠心肌缺血/再灌注损伤保护作用的对比研究

目的观察比较七氟烷预处理对成年及幼年大鼠心肌缺血/再灌注损伤保护作用及可能机制。方法 36只成年♂SD大鼠随机分为3组:对照组(sham 1组),缺血/再灌注组(I/R 1组),七氟烷预处理组(S 1组);36只幼年♂SD大鼠随机分为3组:对照组(sham 2组),缺血/再灌注组(I/R 2组),七氟烷预处理组(S 2组)。采用Langendorff离体大鼠心肌灌注模型。对照组,自然灌流120 min;缺血/再灌注组,平衡灌注30 min,缺血30 min,复灌60 min;七氟烷组,平衡灌注15 min,含七氟烷的K-H液10 min,洗出5 min,缺血30min,再灌注60 min。记录各组心脏在平衡末及复灌15 min的左室舒张末压(LVEDP)、左室发展压(LVDP)、左室压力升高或降低最大速率(±dp/dtmax)、心率(HR)。复灌15 min时,TUNEL法检测凋亡细胞,免疫印迹法(Western blot)半定量检测p-Akt和总Akt的含量;复灌末TTC法计算心肌梗死面积百分比。结果平衡灌注末各组间心功能指标(基础值)差异未见统计学意义(P>0.05)。灌注结束时,S 1组较I/R 1组以及S 2组较I/R 2组心功能明显改善,心肌梗死面积减少和凋亡指数降低(P<0.05),同时p-Akt表达水平升高(P<0.05)。结论 1 MAC的七氟烷预处理可能通过增强Akt的磷酸化来减轻成年及幼年大鼠的心肌缺血/再灌注损伤。     

The role of gasotransmitters NO,H2S and CO in myocardial ischaemia/reperfusion injury and cardioprotection by preconditioning,postconditioning and remote conditioning

Ischaemic heart disease is one of the leading causes of morbidity and mortality worldwide. The development of cardioprotective therapeutic agents remains a partly unmet need and a challenge for both medicine and industry, with significant financial and social implications. Protection of the myocardium can be achieved by mechanical vascular occlusions such as preconditioning (PC), when brief episodes of ischaemia/reperfusion (I/R) are experienced prior to ischaemia; postconditioning (PostC), when the brief episodes are experienced at the immediate onset of reperfusion; and remote conditioning (RC), when the brief episodes are experienced in another vascular territory. The elucidation of the signalling pathways, which underlie the protective effects of PC, PostC and RC, would be expected to reveal novel molecular targets for cardioprotection that could be modulated by pharmacological agents to prevent reperfusion injury. Gasotransmitters including NO, hydrogen sulphide (H₂S) and carbon monoxide (CO) are a growing family of regulatory molecules that affect physiological and pathological functions. NO, H₂S and CO share several common properties; they are beneficial at low concentrations but hazardous in higher amounts; they relax smooth muscle cells, inhibit apoptosis and exert anti-inflammatory effects. In the cardiovascular system, NO, H₂S and CO induce vasorelaxation and promote cardioprotection. In this review article, we summarize current knowledge on the role of the gasotransmitters NO, H₂S and CO in myocardial I/R injury and cardioprotection provided by conditioning strategies and highlight future perspectives in cardioprotection by NO, H₂S, CO, as well as their donor molecules.

Linked Articles

This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-6     

吡那地尔后处理在减轻家兔心肌缺血/再灌注损伤中的作用

目的观察吡那地尔后处理在减轻家兔在体心肌缺血/再灌注损伤的作用,并探讨其可能机制。方法 40只健康成年♂家兔随机分为5组(每组8只),分别为假手术组(Sham)、缺血再灌组(I/R)、缺血后处理组(I-postC)、吡那地尔后处理组(Pina)、吡那地尔后处理+5-羟葵酸组(Pina+5-HD)。采用结扎左冠前降支30 min/复灌120 min的方法复制心肌缺血/再灌注损伤模型。观察并比较各组动物在缺血前、缺血30 min、复灌120 min时心功能指标、血浆CK活性和MDA含量。测定心肌缺血和梗死面积,Bcl-2和Bax mR-NA的表达。结果在复灌120 min时,与I/R组和Pina+5-HD组相比,I-postC组和Pina组动物LVSP明显升高(P<0.05);LVEDP明显降低(P<0.05);血浆CK活性明显降低(P<0.05);血浆MDA含量明显降低(P<0.05);心肌梗死面积明显减小(P<0.05);Bcl-2 mRNA的表达明显增加,BaxmRNA的表达明显降低(P<0.05)。结论吡那地尔后处理可通过模拟缺血后处理的心肌保护机制,减轻心肌缺血/再灌注损伤,其心肌保护的机制可能涉及线粒体ATP敏感性钾通道开放,Bcl-2 mRNA表达的上调和Bax mRNA表达的下调。     

Protective effect of edaravone against renal ischemia/reperfusion injury and compared with ischemic postconditioning in rats

The aim of this study is to clarify whether edaravone postconditioning had protective effect against renal ischemia/reperfusion injury and to compare the protective effect between ischemic postconditioning and edaravone postconditioning. Rats were subjected to 45 min ischemia followed by 24 h reperfusion. The rats were randomly assigned to seven groups: a sham-operated control group, an ischemia/reperfusion group, an ischemic postconditioning group, a normal saline vehicle postconditioning group and an edaravone postconditioning (1, 3, and 6 mg x kg(-1)) group. Renal function was assessed by serum creatinine and BUN concentration, while histological damage of renal tissue was assessed with HE staining. MDA content and SOD activity of renal tissue were determined. TUNEL staining was performed to analyze the apoptosis of the tubular epithelial cells, the protein level of Bcl-2 and Bax in renal tissue was examined by Western blotting. Compared to the ischemia/reperfusion group, edaravone postconditioning significantly decreased serum creatinine and BUN concentration, and ameliorated histological damage of renal tissue. MDA was less after 24 h reperfusion in the edaravone postconditioning group than that in the ischemia/reperfusion group, consistent with an increase in SOD activity. In addition, edaravone postconditioning decreased TUNEL-positive cells and Bax expression, and increased Bcl-2 expression. Results detected in the edaravone postconditioning group showed no significant difference from the ischemic postconditioning group. Edaravone administered during the last 3 min of ischemia, prior to reperfusion induces a pharmacological postconditioning in vivo against renal ischemia/reperfusion injury in rats. This protection is similar to that observed with ischemic postconditioning.     

无创性延迟肢体缺血预适应对糖尿病大鼠心肌缺血/再灌注氧化损伤的影响

目的:观察无创性延迟肢体缺血预适应(NDLIP)对糖尿病(DM)大鼠心肌缺血/再灌注氧化损伤的保护作用。方法:尾静脉注射链脲佐菌素(STZ)制备DM大鼠模型。将DM大鼠随机分成心肌缺血再灌注(I/R)、心肌缺血预适应(MIP)、无创性延迟肢体缺血预适应(NDLIP)组。通过3个循环的左后肢5 min缺血/5 min再灌注,每天1次,连续3 d,建立NDLIP模型。心肌冠状动脉左前降支(LAD)实施3次5 min缺血/5 min再灌注建立MIP模型。各组实施LAD 30 min缺血/120 min再灌注复制I/R模型。用BL-420E生物机能实验系统连续监测心电图(ECG),记录缺血期间室性心律失常(VA)的发生情况。TTC染色测定大鼠心肌I/R后梗死面积(IS)。检测心肌组织中总-超氧化物歧化酶(T-SOD)、锰-超氧化物歧化酶(Mn-SOD)活性及丙二醛(MDA)含量。结果:与I/R组相比,MIP组和NDLIP组室性早搏(VPC)出现时间明显推迟(P<0.01),持续时间明显缩短(P<0.01),室性心动过速(VT)和心室纤颤(VF)发生率都明显降低(P<0.05),IS明显缩小,梗死面积/危险区(IS/A...     

生长激素预处理对大鼠心肌缺血再灌注后细胞凋亡与能量代谢的影响

目的研究生长激素预处理对大鼠心肌缺血再灌注后心肌细胞凋亡及能量代谢的影响。方法42只大鼠采用完全随机设计方法分为3组，假手术组14只（假手术24h）、心肌缺血再灌注组14只、生长激素组14只，后2组均缺血30min，再灌注24h，其中生长激素组的每只大鼠术前皮下肌肉注射生长激素1 U／kg，连续7d，其中第7次皮下注射于手术前进行。前2组每只大鼠相应皮下肌肉注射生理盐水0．5ml／d。每组中均抽取8只大鼠，以TUNEL法检测缺血区心肌细胞凋亡情况，每组中剩余的抽取5只大鼠，以高效液相色谱法测定缺血区心肌三磷酸腺苷（ATP）并进行心肌组织病理、电镜超微结构观察。结果与假手术组比较，心肌缺血再灌注组再灌注24h后缺血区心肌细胞凋亡率和ATP消耗程度均明显上升（P〈0．05），心肌组织病理和超微结构改变明显；与心肌缺血再灌注组比较，生长激素组再灌注24h后缺血区心肌细胞凋亡率和ATP消耗程度均明显改善（P〈0．05），心肌组织病理和超微结构改变明显减轻。结论生长激素能减少心肌缺血再灌注后心肌细胞凋亡和ATP的消耗，说明生长激素对心肌缺血再灌注后的心肌具有保护作用。     

心肌缺血预适应及后适应在再灌注期共同靶点的研究进展

心肌缺血预适应及后适应作为机体的一种内源性保护,分别具有缺血/再灌注损伤保护和再灌注损伤保护功能,尤其是在再灌注期可能存在共同的作用机制,如减少氧自由基生成,激动腺苷受体,募集再灌注损伤营救激酶途径,激活线粒体ATP敏感性钾通道,抑制线粒体渗透性转换孔道开放等。这些共同靶点可以为研制抗再灌注损伤药物提供新的思路。     

Antioxidants in the prevention of myocardial ischemia/reperfusion injury

In acute myocardial ischemia (AMI) the optimal treatment is rapid revascularization by angioplasty or pharmacological thrombolysis. While this is essential to resuscitate the ischemic myocardium, it results in further reperfusion injury and extension of the infarction. The main hypothesis for the mechanism of reperfusion injury is the generation of reactive oxygen species (ROS) to such a degree that endogenous antioxidant mechanisms are overcome and tissue injury results. There is growing evidence that ROS-induced injury may continue for weeks to months as a result of activation of apoptosis. In the longer term, this may result in ventricular remodeling and cardiac failure. Although a number of antioxidants have produced beneficial effects in animal models of AMI, none have proved efficacious in subsequent clinical trials. Drugs that are more specific for the source of ROS generation and that are better able to target the sources of oxidant stress may have greater potential for the prevention of reperfusion injury.