辛伐他汀保护缺血-再灌注损伤心肌的线粒体蛋白质组学研究

目的建立大鼠心肌缺血-再灌注损伤模型,通过蛋白质组学的方法研究辛伐他汀对大鼠缺血-再灌注损伤心肌线粒体代谢的保护作用。方法将大鼠随机分为辛伐他汀干预组(n=14)和生理盐水对照组(n=14),建立缺血-再灌注损伤模型,通过伊文思蓝和TTC染色评估梗死面积,提取大鼠左心室心肌线粒体蛋白行双向凝胶电泳,应用质谱分析鉴定差异蛋白点。结果辛伐他汀组和对照组相比,梗死区与危险区(梗死区+缺血区)的比值有统计学差异(29.4%±8.4%vs57.7%±6.5%,P0.0001);梗死面积与左室面积的比值有统计学差异(15.9%±5.6%vs29.0%±8.9%,P=0.012)。双向凝胶电泳图谱分析有19个蛋白点的表达有差异,质谱鉴定了9种差异蛋白,相比对照组,辛伐他汀组4个蛋白表达上调:三功能酶亚基α(线粒体前体)、电子转移黄素蛋白脱氢酶、肌动蛋白α(心肌)、细胞色素c氧化酶亚基5A亚单位(线粒体前体);5个蛋白表达下调:L-乳酸脱氢酶B链、异柠檬酸脱氢酶[NAD]α亚基(线粒体前体)、α晶状体蛋白B链、内膜蛋白(线粒体)、肌动蛋白类似物(细胞质)。结论辛伐他汀组大鼠心肌在缺血-再灌注损伤后,心肌梗死面积显著减少,辛伐他汀改变线粒体呼吸链、能量代谢等途径上的蛋白,为阐明辛伐他汀保护缺血再灌注损伤提供了理论依据。     

压力超负荷致心力衰竭大鼠解耦联蛋白2表达及心肌能量变化

目的 探讨压力超负荷致心力衰竭大鼠心肌线粒体解耦联蛋白2(uncoupling protein 2,UCP2)表达的改变及其意义.方法 雄性SD大鼠45只随机分为腹主动脉缩窄组(H20w组)、假手术组(SH20w组)和正常对照组(N组)3组,每组15只,H20w组行腹主动脉缩窄术.术后20周,行心脏超声检测心功能、观察大鼠血液动力学参数,高压液相色谱法测量心肌组织腺苷酸含量,密度梯度法提取大鼠心肌线粒体,逆转录聚合酶链反应及Western blot法分析心肌线粒体UCP2表达.结果 大鼠行腹主动脉缩窄术后20周出现心功能减退,血液动力学异常等心力衰竭表现,提示建模成功.同时间比较,H20w组心肌组织内三磷酸腺苷(ATP)、二磷酸腺苷、单磷酸腺苷及磷酸肌酸含量均低于SH20w组和N组.逆转录聚合酶链反应及Westem blot表明H20w组心肌线粒体UCP2表达水平分别较SH20w组高69%、61%,较N组高76%、65%(P<0.01),相关性分析显示UCP2表达量与心肌组织内ATP含量变化呈负相关(r=-0.929,P<0.01).结论 心力衰竭时,心肌线粒体UCP2表达增高,导致心肌ATP含量减少,可能参与了衰竭心肌能量代谢障碍.     

色甘酸钠对大鼠心肌梗死后心肌凋亡及凋亡蛋白的影响

目的 研究肥大细胞脱颗粒程度对心肌梗死后的心肌凋亡及心肌纤维化的影响,探讨细胞凋亡机制在心肌梗死后心室重构中的作用.方法 建立雄性SD大鼠心肌梗死模型,分成假手术组(n=6)、模型组(n=8)、色甘酸钠组(n=7).术后4周,留取心肌标本行TUNEL染色观察心肌细胞凋亡指数(AI),Masson染色检测心肌胶原容积分数(CVF),Western blot法检测Caspase-3、Bcl-2和Bax蛋白表达.结果 与假手术组相比,模型组、色甘酸钠组在AI、CVF、Caspase-3及Bax蛋白表达量等方面均显著升高(P＜0.05),Bcl-2蛋白表达明显下降;色甘酸钠组与模型组相比,AI、CVF、Caspase-3及Bax蛋白表达量均有所下降(P＜0.05),Bcl-2蛋白有所升高,但两者差异无统计学意义(P=0.127).AI与CVF呈正相关(r=0.769,P＜0.01).结论 心肌梗死后心肌凋亡显著增加,抑制肥大细胞脱颗粒可明显减少心肌凋亡,减轻左心室心肌纤维化程度.     

同种异体骨髓间充质干细胞移植对扩张型心肌病心功能衰竭大鼠左心室功能的影响

目的探讨同种异体大鼠骨髓间充质干细胞移植在阿霉素诱导的扩张型心肌病心功能衰竭大鼠心脏内存活、分化的情况及对左心室功能的影响。方法雌性Wistar大鼠55只,随机分成正常对照组(n=10)、模型组(n=15)、诱导前移植组(n=15)和诱导后移植组(n=15)。体外分离培养雄性大鼠骨髓间充质干细胞,传至一代后用10μmol/L5-氮胞苷诱导4周,DAPI标记后,诱导前移植组移植诱导前的骨髓间充质干细胞,诱导后移植组移植诱导后的骨髓间充质干细胞;4周后检测左心室功能及移植细胞存活、分化情况。结果异体骨髓间充质干细胞移植4周后可存活并分化成心肌细胞,表达心肌细胞特异性蛋白;与模型组比较,细胞移植组左心室功能明显改善,且两细胞移植组间差异无显著性。结论同种异体骨髓间充质干细胞移植4周后可存活并分化成心肌细胞,对扩张型心肌病心功能衰竭大鼠的左心室功能有保护作用。     

不同浓度硝酸甘油对心脏缺血/再灌注的作用及ALDH2的作用

目的 探讨不同浓度硝酸甘油(GTN)对离体大鼠心脏缺血/再灌注损伤的作用,进一步分析线粒体乙醛脱氢酶2(ALDH2)在其中的作用.方法 采用离体大鼠心脏Langendorff灌流方法,局部结扎冠状动脉左前降支30 min,复灌30 min复制缺血/再灌注模型.实验分五组,正常对照组,单纯缺血/再灌注组,GTN低浓度组(10 -8 mol/L GTN),中浓度组(10-7 mol/L GTN)及高浓度组(2×10 -6 mol/L GTN).测定心室动力学指标和复灌期间冠脉流出液中乳酸脱氢酶( lactate dehydrogenase,LDH)含量,RT-PCR测定左心室前壁心尖组织线粒体ALDH2基因mRNA表达水平.结果 与单纯缺血/再灌注组相比,GTN低浓度组左心室发展压(LVDP)、室内压最大上升/下降速率(±dp/dtmax)均增高,左心室舒张末压(LVEDP)降低,中浓度组无明显差异,高浓度组LVDP和±dp/dtmax均降低;LVEDP增高.与缺血/再灌注组相比,正常对照组和低浓度GTN组心肌组织ALDH2 mRNA表达增高,中浓度无明显差异,高浓度组大鼠心肌ALDH2 mRNA表达降低.结论 低浓度GTN可对抗心肌缺血/再灌注损伤,高浓度GTN加重损伤,中浓度GTN对损伤影响不大,此现象可能与不同浓度GTN引起心肌ALDH2的释放量不同有关.     

曲美他嗪干预对心力衰竭大鼠心肌细胞线粒体超微结构、心肌细胞凋亡及半胱氨酸天冬氨酸蛋白酶3蛋白、细胞色素C蛋白表达的影响

目的:探讨曲美他嗪干预对心力衰竭(心衰)大鼠左心室心肌细胞线粒体超微结构、心肌细胞凋亡及半胱氨酸天冬氨酸蛋白酶3(caspase-3)蛋白和细胞色素C蛋白表达的影响。方法:雄性wistar大鼠30只随机分为假手术组、心衰模型组、曲美他嗪组,每组10只。除假手术组外,其余两组大鼠采用肾上腹主动脉缩窄法建立慢性心衰模型,其中曲美他嗪组大鼠给予曲美他嗪10 mg/(kg·d)灌胃4 w。观察各组左心室舒张末期压(LVEDP)、左心室压力最大上升及下降速率(±dp/dtmax);苏木素伊红(HE)染色法观察大鼠心肌细胞形态结构;透射电镜观察心肌细胞线粒体超微结构;原位缺口末端标记(TUNEL)法检测心肌细胞凋亡指数(AI);SP免疫组织化学法检测各组大鼠左心室心肌细胞caspase-3蛋白、细胞色素C蛋白的表达。结果:与假手术组比较,心衰模型组大鼠心肌细胞线粒体形态发生明显改变,排列紊乱,空泡变性,LVEDP显著升高(P<0.01),±dp/dtmax明显降低(P<0.01),心肌细胞凋亡指数、caspase-3蛋白及细胞色素C蛋白的表达水平升高,差异均有统计学意义(P<0.01);与心衰模型组相比,曲美他嗪组大鼠心肌细胞线粒体形态变化明显改善,LVEDP明显下降(P<0.01),±dp/dtmax显著升高(P<0.01),心肌细胞凋亡指数、caspase-3蛋白及细胞色素C蛋白的表达水平降低,差异均有统计学意义(P<0.01)。结论:曲美他嗪可有效改善心功能,抑制心肌细胞凋亡,其机制可能与保护心肌细胞线粒体功能有关。     

衰老大鼠心肌线粒体PT孔开放对线粒体呼吸功能的影响

目的研究衰老大鼠心肌线粒体通透性转换(PT)孔开放对线粒体呼吸功能的影响及机制。方法左心室插管检测大鼠心功能;透射电镜检测大鼠心肌组织线粒体形态学改变;线粒体肿胀法检测心肌线粒体PT孔开放程度;氧电极法检测大鼠线粒体呼吸速率;荧光法检测线粒体膜电位。结果同3月龄组大鼠相比,15和18月龄组大鼠线粒体出现空泡肿胀、线粒体内膜脊出现断裂;大鼠左室收缩压(LVSP)和左室压上升/下降最大速率(±dp/dtmax)降低(P0.01);线粒体PT孔开放幅度明显增强(P0.01),左室舒张末压(LVEDP)升高(P0.01);线粒体膜电位下降(P0.01);线粒体呼吸速率明显降低(P0.01)。线粒体PT孔开放抑制了线粒体呼吸功能,降低了线粒体膜电位(P0.01),但是抑制线粒体呼吸功能对线粒体PT孔开放和线粒体膜电位无影响(P0.05)。结论衰老大鼠线粒体PT孔开放可能通过降低线粒体膜电位抑制线粒体呼吸功能。     

咪达普利对舒张功能不全大鼠心功能的保护与减轻心肌线粒体损伤有关

目的探讨咪达普利对舒张功能不全心力衰竭大鼠心脏功能保护作用的机制。方法30只雄性SD大鼠,随机分为对照组、模型组、用药1组、用药2组和用药3组共5组。采用腹主动脉缩窄建立舒张功能不全心力衰竭模型,对照组只开腹和分离腹主动脉。3个用药组大鼠术后分别灌胃给予咪达普利1.5 mg/(kg.d)、3或6 mg/(kg.d);对照组和模型组大鼠灌胃给予同等量的生理盐水共4周。4周末心脏B超检测心功能,颈动脉插管记录血流动力学变化,取心脏称重,计算与体重的比例,分光光度计检测线粒体丙二醛、超氧化物歧化酶和谷胱甘肽过氧化物酶变化,电镜检测心肌线粒体超微结构改变。结果心脏超声心动图发现舒张功能不全心力衰竭组大鼠室间隔和左心室后壁厚度、E/A比值明显增高,血流动力学检测发现收缩压、舒张压、左心室收缩压、左心室舒张期末压升高,左心室松弛时间常数延长,左心室内压最大下降速率下降,心脏指数和左心室质量指数增加。咪达普利使增加的室间隔和左心室后壁厚度、E/A、收缩压、舒张压、左心室收缩压、左心室舒张期末压、心脏指数和左心室质量指数降低,左心室松弛时间常数缩短,左心室内压最大下降速率升高,随着咪达普利剂量的增加,改变的程度越明显。线粒体功能检测发现,舒张功能不全心力衰竭组大鼠超氧化物歧化酶和谷胱甘肽过氧化物酶下降,丙二醛增加,电镜观察发现心肌细胞肌丝排列不整齐、线粒体肿胀及空泡化等线粒体损伤;咪达普利减轻线粒体结构和功能损伤。结论咪达普利通过减轻心肌细胞和线粒体损伤改善舒张功能不全心力衰竭大鼠的心脏功能。     

肿瘤坏死因子α介导大鼠心肌梗死后心功能变化的机制

为探讨大鼠心肌梗死后衰竭心肌肿瘤坏死因子α表达、基质金属蛋白酶活性和核因子κB活化与心肌胶原含量、心功能的相互关系,通过结扎大鼠冠状动脉前降支复制心肌梗死模型,同时设假手术组,分别在4周、8周和12周后检测血流动力学和心功能指标.同时检测左心室非梗死区心肌肿瘤坏死因子α蛋白水平、核因子κB活性、明胶分解活性和心肌胶原容积指数.结果发现,心肌梗死后心肌肿瘤坏死因子α表达显著增加,呈时间依赖性,与心功能呈负相关;心肌梗死后4周、8周和12周时心肌核因子κB活性、基质金属蛋白酶2和9活性以及胶原容积指数均呈进行性增加,而心功能逐渐恶化.以上说明,衰竭心肌核因子κB持续活化、肿瘤坏死因子α过度表达和明胶分解活性增强可能是导致心肌梗死后心室重塑和心力衰竭的重要机制之一.     

SIRT3对SD大鼠体外循环心功能的影响

目的 探讨心肌线粒体去乙酰化酶 SIRT3对大鼠体外循环(CPB)所致急性心功能下降的影响及机制。方法 Sprague-Dawley(SD)成年大鼠30只,随机分为3组:对照组(sham组)、体外循环组(CPB组)、外源性烟酰胺腺嘌呤二核苷酸(NAD+)治疗体外循环组(NAD+治疗组),每组10只（n=10）。麻醉复苏后1 h,采用彩色多普勒超声诊断仪检测左心室收缩末期内径(LVIDs)、左心室舒张末期内径(LVIDd)、短轴缩短率(FS)及左心室射血分数(LVEF)。然后处死SD大鼠,取心肌组织,检测 AMPK、p-AMPK和心肌细胞膜Glut-4的蛋白表达及SIRT3和AMPK的活性。结果 与sham组相比,CPB组在CPB后血糖升高(P<0.05),心功能下降(P<0.05),具体表现为LVIDs和LVIDd值升高(P<0.05)、FS和LVEF值下降(P<0.05),CPB后SD大鼠心肌的SIRT3活性下降(P<0.05),下游的AMPK磷酸化水平及AMPK活性下降以及心肌细胞膜Glut-4的蛋白表达下降（均P<0.05）;预先采用外源性NAD+治疗,可显著降低血糖水平(P<0.05),提高CPB后SD大鼠心肌SIRT3的活性,促进心肌AMPK的磷酸化和该酶活性的升高(均P<0.05),并增加CPB大鼠心肌细胞膜Glut-4蛋白表达(P<0.05);与CPB组相比,NAD+治疗组心功能降低有所改善,表现为LVIDs和LVIDd值下降、FS和LVEF值升高(均P<0.05)。结论 NAD+治疗可明显改善SD大鼠CPB后的心功能,其机制可能与激活SIRT3,进而增加下游AMPK的磷酸化和该酶活性,以及增加心肌细胞膜Glut-4蛋白表达,并促进CPB术后心肌对葡萄糖的摄取和利用以及ATP的生成有关。     

安体舒通对心衰大鼠心肌组织TGF-β/Smads信号通路相关分子表达的影响

目的 观察醛固酮受体阻滞剂安体舒通对心肌梗死后心力衰竭（心衰）大鼠心肌组织中TGF-β/Smads 信号通路相关分子表达的影响,并探讨其意义.方法 健康雄性SD大鼠32只,分为心衰对照组和安体舒通组各11只,假手术组10只,通过结扎冠状动脉构建心肌梗死后心衰模型,假手术组不结扎冠脉.术后2周,假手术组和心衰对照组采用生理盐水、安体舒通组采用安体舒通20 mg/kg灌胃8周.分别于术后2周（灌胃前）、灌胃后8周采用超声心电图监测大鼠左室收缩末期容积（LVESD）、左室舒张末期容积（LVEDD）、左室射血分数（LVEF）和短轴缩短率（FS）.其后处死大鼠并取心脏组织,采用Masson染色测定心肌胶原容积分数（CVF）.采用Real-timePCR法检测三组心肌组织中的TGF-β1、Smad2、Smad3、Smad7 mRNA,Western blot法检测TGF-β1、Smad2、Smad3、Smad7蛋白及胶原纤维Ⅲ蛋白.结果 灌胃前安体舒通组、心衰对照组LVEDD、LVESD较假手术组增加,而EF及FS下降（P均＜0.05）.灌胃后8周,安体舒通组EF、FS高于心衰对照组（P均＜0.05）.心肌CVF心衰对照组＞安体舒通组＞假手术组（P均＜0.05）.大鼠心肌组织中TGF-β1、Smad2、Smad3及Smad7mRNA及其蛋白和胶原纤维Ⅲ蛋白的表达心衰对照组＞安体舒通组＞假手术组（P均＜0.05）.结论 安体舒通可抑制心肌梗死后心衰大鼠TGF-β/Smads信号通路相关分子的表达,改善心肌纤维化.     

Effects of growth hormone in rats with postinfarction left ventricular dysfunction

Summary Growth hormone may affect cardiac function. In rats, chronic hypersecretion of growth hormone leads to increased maximum isometric contractile force of the left ventricular papillary muscle in vitro. In humans, administration of growth hormone can increase myocardial contractility. However, cardiac effects of growth hormone in heart failure or cardiac dysfunction have not been studied to date. The current study was to evaluate the cardiac effects of growth hormone in conscious rats with postinfarction left ventricular dysfunction and sham controls. Ligation of the left coronary artery or sham operation was performed, then 4 weeks after surgery, recombinant human growth hormone (2 mg/kg/day, SC) or vehicle was administered for 15 days. Catheters were implanted 13 days after treatment with growth hormone or vehicle. Hemodynamic parameters were measured in conscious rats 2 days after catheterization. In vehicle-treated rats, left ventricular systolic pressure, maximum dP/dt, and arterial pressure were significantly decreased and left ventricular end-diastolic pressure was significantly increased in the ligation group compared with sham controls. Growth hormone treatment increased left ventricular systolic pressure (p<0.05) and dP/dt (p<0.05) and reduced left ventricular end-diastolic pressure (p<0.05), significantly in the ligated rats. In sham rats, growth hormone tended to decrease arterial pressure but did not alter ventricular contractility. Neither ligation nor growth hormone significantly altered heart rate and right atrial pressure. These results suggest that growth hormone treatment may improve cardiac function by increasing myocardial contractility in cardiac dysfunction or heart failure.     

Myocardial heat shock protein changes in the failing heart following coronary artery ligation

BACKGROUND: Production of several heat shock proteins (Hsp) is enhanced after exposure to stress. There is little information concerning changes in myocardial Hsp under pathophysiological conditions. The aim of this study was to determine alterations in Hsp content in the viable left ventricular myocardium during the development of heart failure following coronary artery ligation (CAL). METHODS: Myocardial infarction was produced by CAL of Wistar rats. One and eight weeks after the operation, haemodynamic parameters of rats with CAL were determined and then expression of Hsp27, Hsp60 and Hsp72 was measured by western blotting. RESULTS: Animals showed a decrease in cardiac output and an increase in left ventricular end-diastolic pressure, symptoms of chronic heart failure (CHF), 8 weeks after CAL. Myocardial Hsp27 and Hsp72 at 1 week after CAL significantly increased, whereas expression of both proteins at 8 weeks was similar to that in rats which underwent a sham operation (without coronary artery ligation). In contrast, Hsp60 at 8 weeks, but not at 1 week, significantly increased in the sham rats. CONCLUSIONS: Diverse changes in myocardial Hsp occurred during the development of CHF.     

卡维地洛对大鼠心肌梗死后心功能和交感神经重构的影响

目的探讨卡维地洛(carvedilol)对大鼠心肌梗死(MI)后心功能和心脏交感神经重构的影响。方法 80只雄性Wistar大鼠随机分为MI组(30只)、carvedilol组(30只)和假手术(SO)组(20只),前两组采用结扎左冠状动脉前降支的方法制备MI模型,SO组只开胸,不结扎血管。术后carvedilol组给予每天两次carvedilol5.0mg/kg灌胃处理,MI组和SO组以等量生理盐水灌胃。8周后,采用多道电生理记录仪测定三组大鼠的心率(HR)、左室舒张末压(LVEDP)、左室收缩压(LVSP)和左室压力上升和下降的最大速率(±dp/dt),并用蛋白印记分析和逆转录多聚酶链反应(RT-PCR)分别观察MI后梗死周边区生长相关蛋白43(GAP43)及酪氨酸羟化酶(TH)蛋白含量和mR-NA表达的变化。结果 8周后,与MI组比较,carvedilol组HR和LVEDP显著下降,LVSP和±dp/dt明显上升(P均0.05);carvedilol组GAP43和TH的蛋白含量与mRNA表达亦明显降低(P0.05)。结论 carvedilol能显著改善大鼠MI后心功能,并抑制梗死周围区交感神经重构。     

心力衰竭大鼠心室肌细胞表达bax、bcl-2的性别差异及保心康的调节作用

目的:研究心力衰竭的大鼠左心室肌细胞表达bax和bcl-2蛋白的性别差异性,并观察保心康的作用。方法:普通级SD大鼠随机分为保心康组、蒸馏水组和假手术组,用腹主动脉缩窄造成心力衰竭的模型,流式细胞仪检测心室肌细胞内bax和bcl-2的表达率。结果:3组雌性大鼠心脏、左心室重量均较雄性的小;假手术组雌性大鼠的心脏质量指数也较雄性低,其他2组大鼠的心脏质量指数无性别差异;3组大鼠bax蛋白的表达率的无性别差异,雌性bcl-2的表达率均高于相应的雄性大鼠;保心康组雌雄性大鼠左心室肌细胞bcl-2的表达均升高,bax的表达均降低。结论:在充血性心力衰竭大鼠模型左心室肌细胞中,bax的表达雌雄性相似,但bcl-2的表达雌性较雄性高;保心康可上调左心室心肌细胞bcl-2的表达,下调bax的表达,从而抑制心肌细胞的凋亡。     

β受体阻断剂对大鼠急性心肌梗死后G蛋白及心功能的影响

目的 观察β受体阻断剂对大鼠急性心肌梗死(AMI)后G蛋白及心功能变化的影响.方法 复制大鼠AMI模型,随机分3组,分别给予选择性β1受体阻断剂美托洛尔(美托洛尔组)、非选择性β受体阻断剂卡维地洛(卡维地洛组)及安慰剂(对照组),另设假手术组.8周后测定AMI后血流动力学变化;采用Western印迹杂交法研究兴奋性G蛋白(Gs)和抑制性G蛋白(Gi)的变化.结果 与假手术组比较,AMI组主动脉收缩压(SBP)、主动脉舒张压(DBP)、左心室收缩压(LVSP)、左心室内压最大收缩和舒张速率(±dp/dtmax)均显著下降,左心室舒张末压(LVEDP)显著升高[(6.0±2.9)mm Hg与(29.7±5.6)mm Hg] ;Gs蛋白分别为(101.9±3.5)%和(115.9±11.2)%,Gi蛋白显著升高[分别为(102.5±4.9)%和(238.4±68.0)%] .与AMI组比较,美托洛尔、卡维地洛组LVSP、±dp/dtmax升高,LVEDP下降[(10.3±4.9)mm Hg、(7.9±3.8)mm Hg] ;Gi显著下降,分别为(128.1±17.2)%与(104.5±13.7)%.卡维地洛组LVEDP和Gi下降较美托洛尔组明显. 结论 卡维地洛能有效抑制AMI后G蛋白的变化并改善心功能,且优于美托洛尔,可能与其β2受体阻断作用有关.     

心衰大鼠微颗粒对内皮细胞迁移的抑制作用

目的 检测慢性心力衰竭（HF）大鼠循环微颗粒（MPs）数量及蛋白浓度的变化并观察其对人脐静脉内皮细胞迁移能力的影响。 方法 将SD大鼠随机分为手术组（n=15）和伪手术组（n=6）,采用腹主动脉缩窄法建立慢性HF大鼠模型,术后12周采用超声心动图检测心脏功能,HE染色检测心脏形态学改变。应用流式细胞术检测大鼠的总循环MPs及膜联蛋白（Annexin）Ⅴ阳性的MPs数量,BCA法检测总循环MPs的蛋白量。划痕实验观察各组大鼠MPs对内皮细胞的影响。 结果 ①术后12周,与伪手术组大鼠相比,手术组大鼠心功能下降,表现为左室收缩末期内径（LVIDs）与左室舒张末期内径（LVIDd）显著增大（均P<0.01）,左室射血分数（LVEF）与左室短轴缩短率（LVFS）明显减小（均P<0.01）。HE染色结果显示,手术组大鼠的心肌结构紊乱,表明慢性HF大鼠模型建立成功。②手术组大鼠总循环MPs及Annexin Ⅴ（+） MPs的数量和总循环MPs的蛋白量显著高于伪手术组（均P<0.01）。③手术组大鼠循环MPs作用内皮细胞24 h后,其迁移能力下降（P<0.05）;孵育36 h和48 h时,细胞迁移率显著下降（P<0.01）。 结论 在慢性HF大鼠模型中循环MPs的数量及蛋白量显著升高,HF大鼠的循环MPs可抑制内皮细胞的迁移功能。     

Converting enzyme inhibition after experimental myocardial infarction in rats: comparative study between spirapril and zofenopril.

STUDY OBJECTIVE--The aim was to compare the effects of two novel angiotensin converting enzyme (ACE) inhibitors, spirapril and zofenopril, on cardiac remodelling in rats with congestive heart failure after myocardial infarction. Spirapril contains no sulphydryl group, whereas zofenopril is a sulphydryl containing ACE inhibitor. DESIGN--Experimental myocardial infarction was induced by ligation of the left coronary artery. Sham operated animals served as controls. Treatment with spirapril (2-2.5 mg.kg-1.d-1) or zofenopril (12-15 mg.kg-1.d-1) added to the drinking water was started immediately after myocardial infarction or sham operation and continued for six weeks. After the treatment period, all rats were killed. The heart was rapidly removed and perfused as described by Langendorff. Heart rate and left ventricular pressure were measured both at baseline and during stimulation with isoprenaline (6 nM). Heart and lung weights were determined. SUBJECTS--Normotensive male Wistar rats (220-240 g) were used. MEASUREMENTS AND MAIN RESULTS--Experimental myocardial infarction considerably increased left ventricular cavity volume. Chronic treatment with either spirapril or zofenopril significantly attenuated this increase in volume. In infarcted rats, the increase in total heart and lung weight was also significantly reduced by chronic treatment with spirapril and zofenopril, indicating that these compounds reduce cardiac mass and pulmonary congestion in congestive heart failure due to myocardial infarction. There were no significant differences between treatment with spirapril and zofenopril. In the isolated and perfused rat heart, myocardial infarction significantly decreased both heart rate and left ventricular pressure. Converting enzyme inhibition only affected heart rate. Heart rate was significantly higher in infarcted animals treated with spirapril and zofenopril than in untreated infarcted animals. CONCLUSIONS--Both spirapril and zofenopril attenuated ventricular enlargement and cardiac hypertrophy in rats with congestive heart failure after myocardial infarction when treatment was started in the acute phase of myocardial infarction. No additional role could be attributed to the sulphydryl moiety of zofenopril. It is also suggested that these two ACE inhibitors modify cardiac sympathetic activity in rats with congestive heart failure, but more studies are needed to confirm these findings.     

非诺贝特对慢性心力衰竭大鼠心肌能量代谢和心室重构的影响

目的研究非诺贝特对慢性心力衰竭(CHF)大鼠心肌能量代谢和心室重构的影响。方法健康雄性Wistar大鼠随机选为假手术组18只;采用腹主动脉缩窄术制备CHF、并成功存活的38只再随机分为对照组20只、非诺贝特组18只[非诺贝特150 mg/(kg·d)],干预10周。计算左心室心肌重构指数、胶原容积分数(CVF)、心肌线粒体损伤程度分级用Flameng评分,免疫印迹法测过氧化物酶体增殖物激活受体α(PPARα)、中链酰基辅酶A脱氢酶(MCAD)、肌型肉碱棕榈酰转移酶1(MCPT 1)蛋白表达,RT-PCR测PPARα、MCAD和MCPT-1mRNA表达。结果与假手术组比较,对照组及非诺贝特组左心室心肌重构指数、CVF和Flameng评分均升高(P<0.05);非诺贝特组左心室心肌重构指数高于对照组、CVF和Flameng评分低于对照组(P<0.05);与假手术组比较,对照组、非诺贝特组心肌PPARα、MCPT-1、MCAD蛋白和基因表达均下调(P<0.05);非诺贝特组表达较对照组上调(P<0.05)。结论非诺贝特通过增强脂肪酸氧化,减轻线粒体损伤,改善心室重构,减轻心肌纤维化。     

Dietary ω-3 fatty acids alter cardiac mitochondrial phospholipid composition and delay Ca-induced permeability transition

Consumption of ω-3 fatty acids from fish oil, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), decreases risk for heart failure and attenuates pathologic cardiac remodeling in response to pressure overload. Dietary supplementation with EPA + DHA may also impact cardiac mitochondrial function and energetics through alteration of membrane phospholipids. We assessed the role of EPA + DHA supplementation on left ventricular (LV) function, cardiac mitochondrial membrane phospholipid composition, respiration, and sensitivity to mitochondrial permeability transition pore (MPTP) opening in normal and infarcted myocardium. Rats were subjected to sham surgery or myocardial infarction by coronary artery ligation (n = 10–14), and fed a standard diet, or supplemented with EPA + DHA (2.3% of energy intake) for 12 weeks. EPA + DHA altered fatty acid composition of total mitochondrial phospholipids and cardiolipin by reducing arachidonic acid content and increasing DHA incorporation. EPA + DHA significantly increased calcium uptake capacity in both subsarcolemmal and intrafibrillar mitochondria from sham rats. This treatment effect persisted with the addition of cyclosporin A, and was not accompanied by changes in mitochondrial respiration or coupling, or cyclophilin D protein expression. Myocardial infarction resulted in heart failure as evidenced by LV dilation and contractile dysfunction. Infarcted LV myocardium had decreased mitochondrial protein yield and activity of mitochondrial marker enzymes, however respiratory function of isolated mitochondria was normal. EPA + DHA had no effect on LV function, mitochondrial respiration, or MPTP opening in rats with heart failure. In conclusion, dietary supplementation with EPA + DHA altered mitochondrial membrane phospholipid fatty acid composition in normal and infarcted hearts, but delayed MPTP opening only in normal hearts.