缬沙坦对心力衰竭时心肌钙调节蛋白作用的研究

目的:研究缬沙坦对心力衰竭(HF)时肌浆网(SR)钙离子调节蛋白的保护作用.方法:采用腹主动脉-下腔静脉造瘘术建立幼鼠HF模型,术后8周随机分为2组:未治疗组和治疗组(管饲缬沙坦),另设假手术组.对各组幼鼠左室组织提取SR膜,Western blotting法测定受磷蛋白(PLB)磷酸化水平,荧光分光光度仪检测钙离子(Ca2 )的重吸收和渗漏.结果:与假手术组比较,未治疗组体重降低(P<0.01),左室相对质量(LVRW)、右室相对质量(RVRW)均明显升高(P<0.01),16位丝氨酸磷酸化-受磷蛋白(Ser-16-PLB)蛋白量显著降低(P<0.01);与未治疗组比较,治疗组体重(P<0.01)升高,LVRW、RVRW降低(P<0.01),Ser-16-PLB蛋白量明显升高(P<0.01),接近假手术组水平;3组总PLB蛋白量差异无统计学意义(P>0.05);若分别向含有3组SR的缓冲液加入ATP(0.5 mmol/L)后,未治疗组的Ca2 的重吸收量同假手术组和治疗组比较,明显降低(P<0.01);当分别向含有3组SR的缓冲液中加入毒胡萝卜内酯(1μmol/L)后,未治疗组同另外2组比较出现明显的Ca2 渗漏(P<0.01);而当毒胡萝卜内酯(1μmol/L)和FKBP抑制剂FK506(30.μmol/L)一起加入3组SR的缓冲液中,假手术组、治疗组出现明显的Ca2 渗漏(P<0.01),而未治疗组较单独加入毒胡萝卜内酯时Ca2 渗漏仅轻微增多(P>0.05).结论:HF时心肌组织肥厚,细胞Ca2 重吸收量降低、渗漏明显,心肌PLB磷酸化水平显著降低.缬沙坦一方面抑制Ca2 渗漏,另一方面提高PLB的磷酸化水平,恢复Ca2 -ATP酶的Ca2 重吸收能力,提高心脏功能并有效抑制心室重塑.     

缬沙坦对心力衰竭家兔肌质网钙ATP酶表达及功能的影响

目的 探讨家兔慢性心力衰竭时心肌肌质网钙ATP酶（SERCA2）表达和功能的改变及血管紧张素Ⅱ受体拮抗剂缬沙坦长期干预的意义。方法27只家兔随机分为3组,假手术组、心力衰竭组和缬沙坦组各9只。通过超容量负荷联合压力负荷建立家兔心力衰竭模型,于术后7周观察左心室结构、血流动力学的变化及SERCA2的表达和功能的改变。结果与假手术组比较,心力衰竭组左心室质量指数【（1．32±0．06）vS（3．61±0．09）g／kg】、左心室舒张末压【（-0．50±1．05）vs（23．00±2．37）mmHg）】显著升高（P〈0．05）,左心室短轴缩短率【（37．83±3．58）％vs（17．38±3．13）％】及左室射血分数【（72±5）％vS（38±6）％】明显降低（P〈0．05）;与心力衰竭组比较,缬沙坦组左心室质量指数和左心室舒张末压显著降低【（2．07±0．14）g/kg;（2．17±0．72）mmHg;P〈0．05】;左心室短轴缩短率及左室射血分数明显升高【（33．8±2．9）％;（65±4）％;P〈0．05]。心力衰竭组SERCA2的表达【（0．69±0．04）vS（1．02±0．02）】和功能【（54．4±7．9）％w（95．5±2．1）％】显著低于假手术组（P〈0．05）。缬沙坦组SERCA2的表达和功能显著高于心力衰竭组[（0．91±0．02）;（81．7±4．9）％;P〈0．05]。结论缬沙坦长期干预,能够改善心力衰竭心脏舒缩功能,可能与增加SERCA2的表达和提高其功能有关。     

二氮嗪对大鼠缺血再灌注损伤脑组织线粒体ATP酶活性的影响

目的 探讨线粒体ATP敏感性钾通道开放剂二氮嗪对大鼠局灶性脑缺血再灌注损伤脑组织线粒体ATP酶活性的影响.方法 采用改良线栓法建立大鼠局灶性大脑中动脉缺血再灌注损伤模型.将21只Wistar雄性大鼠随机分为假手术组(N组)、缺血再灌注组(IR组)、二氮嗪干预组(DZ组).缺血1 h再灌注24 h后留取标本,测定脑组织线粒体Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性的变化.结果 与假手术组比较,缺血再灌注组Na+-K+-ATPase、Ca2+-Mg2+-ATP酶活性明显降低(P<0.05);二氮嗪干预组Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性均较缺血再灌注组有不同程度的提高(P<0.05).结论 二氮嗪预处理能通过提高脑组织线粒体Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性,减轻脑缺血再灌注损伤,保护神经元线粒体的功能,有效维持大脑能量代谢,发挥脑保护作用.     

肌浆网钙ATP酶高表达对大鼠心肌梗死的影响

目的心肌梗死后心力衰竭主要表现为肌浆网钙释放减少和舒张期细胞浆钙浓度的增加。心肌细胞的肌浆网钙ATP酶(SERCA)起重要的作用。心肌梗死后常伴有SERCA表达的下降。我们通过转基因方法增加SERCA的表达,研究其对心梗后的心肌功能、左心室重构和心律失常的作用。方法将月龄匹配的过表达37%心肌SERCA2a蛋白质的转基因大鼠(TG)和对照野生型(WT)大鼠,通过结扎左冠状动脉诱发心肌梗死。采用动态心电图和心脏超声对心梗后的心律失常和左心室功能进行测定。结果心肌梗死后24hTG的死亡率高于WT(71%对35%,P<0.001),并伴有较高的室性心律失常发生率,后者可被利多卡因所预防。1个月后TG心肌舒张功能明显较WT改善,左心室重构减少,但左室收缩功能无明显改变。结论转基因高表达SERCA2a可以改善心梗后1个月的心肌舒张功能、减少重构,但同时伴有心梗急性期死亡率和心律失常发生率的增高。     

肌浆网钙ATP酶高表达对大鼠心肌梗死的影响

目的:心肌梗死后心力衰竭主要表现为肌浆网钙释放减少和舒张期细胞浆钙浓度的增加.心肌细胞的肌浆网钙ATP酶(SERCA)起重要的作用.心肌梗死后常伴有SERCA表达的下降.我们通过转基因方法增加SERCA的表达,研究其对心梗后的心肌功能、左心室重构和心律失常的作用. 方法:将月龄匹配的过表达37%心肌SERCA2a蛋白质的转基因大鼠(TG)和对照野生型(WT)大鼠,通过结扎左冠状动脉诱发心肌梗死.采用动态心电图和心脏超声对心梗后的心律失常和左心室功能进行测定. 结果:心肌梗死后24 h TG的死亡率高于WT(71%对35%,P＜0.001),并伴有较高的室性心律失常发生率,后者可被利多卡因所预防.1个月后TG心肌舒张功能明显较WT改善,左心室重构减少,但左室收缩功能无明显改变. 结论:转基因高表达SERCA2a可以改善心梗后1个月的心肌舒张功能、减少重构,但同时伴有心梗急性期死亡率和心律失常发生率的增高.     

肌浆网Ca2+ATP酶在充血性心力衰竭中的研究

充血性心力衰竭(CHF)是各种心脏病终末期的共同归宿,发病率和死亡率均较高.研究表明,肌浆网膜上几个关键调节分子的功能障碍引起心肌细胞内钙调节的内在缺损,在CHF的发病过程中发挥了重要的作用.本文对肌浆网Ca2 ATP酶的蛋白结构、调节机制,在CHF的变化及其在CHF基因治疗方面应用的进展作一综述.     

ATP酶在细菌潜生体相关的IBS大鼠模型肠黏膜中的变化

目的:研究细菌潜生体相关的肠易激综合征(irritable bowel syndrome,IBS)大鼠模型肠黏膜ATP酶的变化.方法:Wistar大鼠分为正常对照组和细菌潜生体相关的IBS大鼠模型组.采用无机磷法检测大鼠回盲部黏膜ATP酶活性,高效液相色谱法检测回盲部黏膜细胞的腺苷酸能荷及ATP与总腺苷酸库比值,MTT法检测回盲部黏膜呼吸酶活性.结果:与正常对照组相比较,IBS大鼠模型组回盲部肠黏膜Na+-K+-ATP酶(22.44±5.54 vs14.20±3.03,P<0.01),Ca2+-Mg2+-ATP酶均显著下降(16.46±1.86 vs 10.63±1.78,P<0.01),ATP显著降低(0.96±0.18 v s 0.48±0.20,P<0.01),同时呼吸酶活性显著变化(0.50±0.07vs 0.21±0.05,P<0.01).结论:IBS大鼠回盲部黏膜ATP酶活性显著降低,与能量代谢降低相关,这可能是引起肠黏膜屏障功能受损的重要原因,与IBS病因相关.     

D-半乳糖诱导心肌细胞非酶糖基化对钙调节蛋白的影响

目的 研究D-半乳糖诱导衰老的心肌细胞中的非酶糖基化反应,及其对心肌细胞内钙调节蛋白水平的影响. 方法 实验用5 g/L D-半乳糖干预培养心肌细胞建立衰老模型.显微镜下观察心肌细胞的形态和搏动情况.以β-半乳糖苷酶染色观察细胞衰老,ELISA法检测心肌细胞晚期糖基化终产物(AGEs)的含量,采用western blot检测肌浆网Ca2+-ATP酶(SERCA,心脏主要是SERCA2a)及受磷蛋白(PLN)的含量. 结果 D-半乳糖诱导的心肌细胞内β-半乳糖苷酶染色阳性率显著高于正常对照组[(75.6±4.9)%和(17.15±2.9)%,P＜0.01)];细胞内AGEs较正常对照组明显增高[(702.58±32.16)pg/ml和(93.22±26.14)pg/ml,P＜0.01];SERCA2a含量明显下降与正常对照组比值为0.39±0.05(P＜0.01);PLN含量明显下降与正常对照组比值为0.27±0.03(P＜0.01);同时伴有心肌细胞形态和搏动的异常. 结论 D-半乳糖可通过心肌细胞的非酶糖基化诱导的心肌细胞老化,同时降低心肌细胞内的SERCA2a、PLN蛋白含量,影响心肌细胞的舒缩活动.     

应用微电极阵列记录技术研究抑郁大鼠整体心脏心肌电生理特性

目的研究慢性应激对抑郁大鼠心房、心室场电位时程(FAPD)的影响。方法随机将20只大鼠分为对照组、抑郁组,对抑郁组大鼠进行连续21天的慢性应激。应用微电极阵列技术(MEA)记录心房、心室肌场电位波形、心房、心室FAPD。结果抑郁组大鼠慢性应激后的糖水消耗试验、自主活动得分均明显低于对照组(P<0.01)。MEA记录技术可以记录到60个位点心房、心室肌FAPD不同的波形;抑郁组大鼠心房FAPD高于对照组(83.14±4.61msvs45.76±3.66ms,P<0.05)。两组心室肌FAPD无差异。结论慢性应激所致的抑郁可明显延长大鼠心房FAPD,这可能是抑郁导致心律失常的机制之一。     

亚硝酰氢对冠心病心力衰竭大鼠心肌线粒体功能的影响

目的 探讨亚硝酰氢对心肌梗死后心力衰竭大鼠心肌线粒体Na ,K -ATP酶和Ca₂ -ATP酶及线粒体呼吸链复合体I、IV活性的的影响。方法 结扎大鼠前降支制作心肌梗死后心力衰竭模型,35只Wistar大鼠随机分为假手术组、心力衰竭模型组、亚硝酰氢组。分别给予各组大鼠皮下注射0.9%生理盐水2ml或亚硝酰氢供体0.1mg/100g,4周后差速离心法提取线粒体,测量其Na ,K -ATP酶与Ca₂ -ATP酶活性;应用紫外分光光度法测定缺血再灌注后心肌线粒体呼吸链复合体I、IV的活性。结果 与模型组相比,亚硝酰氢组大鼠线粒体Na _,K -ATP酶和Ca₂ -ATP酶活性及线粒体呼吸链复合体I、IV活性明显增加。 结论 亚硝酰氢改善心力衰竭大鼠心功能的作用通过增加线粒体Na ,K -ATP酶和Ca₂ -ATP酶活性及线粒体呼吸链复合体I、IV活性而实现。     

rAAV-asPLB transfer attenuates abnormal sarcoplasmic reticulum Ca2+ -ATPase activity and cardiac dysfunction in rats with myocardial infarction

BACKGROUND: Diminished myocardial sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) activity and upregulated phospholamban (PLB) level during cardiac dysfunction, had been reported in many studies. AIMS: The current study was designed to examine the effects of rAAV-antisense phospholamban (asPLB) gene transfer on cardiac function, SERCA expression and activity, as well as PLB expression and phosphorylation (Pser16-PLB), in a rat myocardial infarction (MI) model. METHODS AND RESULTS: Rat MI model was generated by ligating the left anterior descending coronary artery. Four weeks later, left ventricular ejection fraction (LVEF), left ventricular systolic pressure (LVSP), the maximal rates of increase and decrease in intraventricular pressure (+/-dp/dt(max)) were significantly depressed, and left ventricular end diastolic pressure (LVEDP) was increased. Myocardial PLB was markedly increased while both SERCA activity and Pser16-PLB level were decreased. In rAAV-asPLB transfected rats, rAAV-asPLB, which was injected into the myocardium around the infarction area immediately after the coronary artery ligation, effectively attenuated the depression of cardiac function, significantly inhibited the expression of PLB, restored Pser16-PLB level and enhanced myocardium SERCA activity. CONCLUSION: rAAV-asPLB transfer in rats with MI effectively prevented the progression of heart failure.     

Dyssynchrony of Ca2+ release from the sarcoplasmic reticulum as subcellular mechanism of cardiac contractile dysfunction

Cardiac contractile function depends on coordinated electrical activation throughout the heart. Dyssynchronous electrical activation of the ventricles has been shown to contribute to contractile dysfunction in heart failure, and resynchronization therapy has emerged as a therapeutic concept. At the cellular level, coupling of membrane excitation to myofilament contraction is facilitated by highly organized intracellular structures which coordinate Ca²⁺ release. The cytosolic [Ca²⁺] transient triggered by depolarization-induced Ca²⁺ influx is the result of a gradable and robust high gain process, Ca²⁺-induced Ca²⁺ release (CICR), which integrates subcellular localized Ca²⁺ release events. Lack of synchronization of these localized release events can contribute to contractile dysfunction in myocardial hypertrophy and heart failure. Different underlying mechanisms relate to functional and structural changes in sarcolemmal Ca²⁺ channels, the sarcoplasmic Ca²⁺ release channel or ryanodine receptor, RyR, their intracellular arrangement in close proximity in couplons and the loss of t-tubules. Dyssynchrony at the subcellular level translates in a reduction of the overall gain of CICR at the cellular level and forms an important determinant of myocyte contractility in heart failure.     

Inhibition of carnitine synthesis modulates protein contents of the cardiac sarcoplasmic reticulum Ca2+-ATPase and hexokinase type I in rat hearts with myocardial infarction

It was previously reported than inhibition of carnitine synthesis by 3-(2,2,2-trimethyl-hydrazinium) propionate (MET-88) restores left ventricular (LV) systolic and diastolic function in rats with myocardial infarction (MI). Preservation of the calcium uptake function of sarcoplasmic reticulum Ca²⁺-ATPase (SERCA2) is one of the possible mechanisms by which MET-88 alleviates hemodynamic dysfunction. To test this hypothesis, the effects of MET-88 on protein content of SERCA2 were evaluated using the same rat model of heart failure. Myocardial protein content of hexokinase, which is one of the key enzymes of glucose utilization, was also measured. Either MET-88 (MET-88 group) or a placebo (MI group) was administered for 20 days to rats with MI induced by coronary artery ligation. The control group underwent sham surgery (no ligation) and received placebo. In LV myocardial homogenates, the myocardial SERCA2 protein content was 32% lower (p<0.05) in the MI group than in the control group. However, in the MET-88 group myocardial SERCA2 content was the same as in the control group. Hexokinase I protein content was 29% lower (p<0.05) in the MI group compared with the control. In contrast, hexokinase II protein content did not differ significantly among the three groups. Consequently, inhibition of carnitine synthesis ameliorates depression of SERCA2 and hexokinase I protein content which may reduce tissue damage caused by MI. Received: 26 July 1999 Returned for 1. revision: 14 September 1999 1. Revision received: 14 December 1999 Returned for 2. revision: 26 January 2000 2. Revision received: 28 February 2000 Accepted: 6 April 2000     

慢性心房颤动患者心房肌浆网钙离子ATP酶及罗纳丹受体mRNA表达变化的研究

研究慢性心房颤动 (简称房颤 )患者Ca2 + 调节蛋白 肌浆网Ca2 + ATP酶及罗纳丹受体 (RyR)mRNA表达的改变 ,探讨房颤时心房肌细胞钙超载的原因及其在房颤发生和维持中的作用。选择 2 0例风湿性心脏病 (以二尖瓣狭窄为主 )接受瓣膜置换术者 ,于术中插管前取右心耳组织约 10 0mg ,采用逆转录 聚合酶链式反应技术 ,测定肌浆网Ca2 + ATP酶及RyR2 mRNA的变化。结果 :房颤者肌浆网Ca2 + ATP酶及RyR2 mRNA水平较窦性心律者明显下调 (分别为 0 .85 4± 0 .2 0 7vs 1.832± 0 .379,P <0 .0 0 1;1.4 12± 0 .319vs 2 .2 5 0± 0 .4 6 8,P <0 .0 5 ) ,且与临床血流动力学参数及性别、年龄无显著相关性。结论 :房颤患者肌浆网Ca2 + ATP酶及RyR2 mRNA表达水平下调 ,表明心房肌浆网钙离子调节蛋白可能参与房颤的发生或维持     

过表达肌浆网钙ATP酶治疗实验性慢性缺血性心力衰竭

目的 研究肌浆网钙ATP酶2a(SERCA2a)基因过表达对慢性缺血性心力衰竭(心衰)心功能及心肌内质网应激(ERS)相关凋亡的影响.方法采用ameroid环束扎小型猪前降支制备慢性缺血性心衰模型.开胸心肌内注射重组腺相关病毒以过表达SERCA2a或对照报告基因绿色荧光蛋白.60 d后检测血流动力学、SERCA2a的表达和活性、心肌凋亡及ERS标志蛋白-分子伴侣GRp78、凋亡蛋白caspase-12的表达.结果基因转导后60 d,与心衰对照及报告基因组相比,转基因组SERCA2a蛋白表达和活性显著增高,心功能参数改善,心肌凋亡指数降低,伴GRP78和活化caspase12表达下降.结论过表达SERCA2a可改善慢性缺血性心衰的心脏功能,其机制可能涉及减轻ERS相关的心肌细胞凋亡.

Abstract：

Objective Chronic myocardial ischemia (CMI) has become the most importat cause of heart failure (HF) all over the world. The aim of the current study was to investigate the effects of Sarcoendoplasmic reticulum calcium ATPaee 2a (SERCA2a) gene transfer on cardiac function and endoplasmic reticulum stress (ERS) associated myocardial apoptosis in a minipig HF animal model induced by CMI. Methods HF was induced in minipigs by implantation of ameroid constrictor in the initial segment of left anterior descending (LAD) branch of coronary artery. After confirmation of myocardial perfusion defects and cardiac function impairment by myocardial perfusion imaging and echocardiography, animals were divided into 4 groups (n =4 each): HF group, HF + enhanced green fluorescent protein (EGFP) group,HF + SERCA2a group, and shamed animals as control group. A total amount of 1×1012 v.g. Of rAAV1EGFP or rAAV1-SERCA2a were injected intramyocardially to each animal of HF + EGFP and HF +SERCA2a groups. Sixty days after gene transfer, protein level and activity of SERCA2a were examined,cardiac functions and changes of serum inflammatory and neuro-hormonal factors were determined. Apoptotic index of the ischemic myocardium, protein levels of ER stress marker glucose regulated protein 78 ( GRP 78) and ER stress specific apoptotic marker caspase-12 were also assayed. Results At the study end,echocardiographic and hemodynamic measurements indicated a significant improvement of both cardiac systolic and diastolic function in HF + SERCA2a group compared with HF/HF + EGFP groups [LVEF (60.2±8.6)%vs (44.2±7.1)% and (46.8±6.7)%, Ev/Ay 1.28±0.24 vs 0.77 ±0.17 and 0.80±0.21, +dp/dtmax(2713.9 ±434.0) mm Hg/s ( 1 mm Hg =0.133 kPa) vs (1892.3 ±434.2) mm Hg/s and (1931.2±397.4)mm Hg/s, -dp/dtmax (1422.1±334.4) mm Hg/s vs (848.3±308.3) mm Hg/s and (849.5±278.3)mm Hg/s, P＜0.05], along with increase in both SERCA2a protein level (1.13±0.26 vs 0.73 ±0.17 and 0.64±0.18, P＜0.05) and activity [(16.2±5.5) IU/ml vs (7.9±3.1) IU/ml and (7.5 ±2.8)IU/ml, P ＜0.05] compared with HF/HF + EGFP groups. Serum concentrations of inflammatory factor tumor necrotic factor α [(382.3±114.4) ng/L vs (732.3±201.4) ng/L and (689.8±192 5) ng/L, P＜0. 05], neural-hormonal factors brain natriuretic peptide [(142.6±45.3) ng/L vs (422.3±113.6) ng/L and(393.7 ±103.3)ng/L, P＜0.01], endothelin-1 [(111.4 ±37.5)ng/L vs (193.5 ±54.3)ng/L and (201.0±72.1)ng/L,P＜0.05] and angiotensin Ⅱ[(189.7±65.2)μg/L vs (538.3 ± 135.2) μg/L and ( 525.5±144.1)μg/L, P＜0.01] were also significantly decreased in HF + SERCA2a group compared with HF/HF + EGFP groups. The apoptotic index [(12.71±4.11)% vs(23.22±7.23) % and (24.31±6.38)%, P＜0.05], protein levels of GRP78 (1.27±0.33 vs 3.23±1.14 and 4.18±1.13, P＜0.05)and protein level ratios of cleaved caspase-12 to total caspase-12[(4.62±1.93)% vs (9.71±2.70)% and (10.14±2.81)%, P＜0.05] were also significantly reduced in the ischemic myocardium of HF+SERCA2a group compared with the HF/HF + EGFP groups. Conclusion Overexpression of SERCA2a significantly improved cardiac systolic and diastolic function in this HF model partly through attenuation of ER stress related myocardial apoptosis, suggesting its therapeutic potential for CM1 related heart failure.     

过表达肌浆网钙ATP酶治疗实验性慢性缺血性心力衰竭

Objective Chronic myocardial ischemia (CMI) has become the most importat cause of heart failure (HF) all over the world. The aim of the current study was to investigate the effects of Sarcoendoplasmic reticulum calcium ATPaee 2a (SERCA2a) gene transfer on cardiac function and endoplasmic reticulum stress (ERS) associated myocardial apoptosis in a minipig HF animal model induced by CMI. Methods HF was induced in minipigs by implantation of ameroid constrictor in the initial segment of left anterior descending (LAD) branch of coronary artery. After confirmation of myocardial perfusion defects and cardiac function impairment by myocardial perfusion imaging and echocardiography, animals were divided into 4 groups (n =4 each): HF group, HF + enhanced green fluorescent protein (EGFP) group,HF + SERCA2a group, and shamed animals as control group. A total amount of 1×1012 v.g. Of rAAV1EGFP or rAAV1-SERCA2a were injected intramyocardially to each animal of HF + EGFP and HF +SERCA2a groups. Sixty days after gene transfer, protein level and activity of SERCA2a were examined,cardiac functions and changes of serum inflammatory and neuro-hormonal factors were determined. Apoptotic index of the ischemic myocardium, protein levels of ER stress marker glucose regulated protein 78 ( GRP 78) and ER stress specific apoptotic marker caspase-12 were also assayed. Results At the study end,echocardiographic and hemodynamic measurements indicated a significant improvement of both cardiac systolic and diastolic function in HF + SERCA2a group compared with HF/HF + EGFP groups [LVEF (60.2±8.6)%vs (44.2±7.1)% and (46.8±6.7)%, Ev/Ay 1.28±0.24 vs 0.77 ±0.17 and 0.80±0.21, +dp/dtmax(2713.9 ±434.0) mm Hg/s ( 1 mm Hg =0.133 kPa) vs (1892.3 ±434.2) mm Hg/s and (1931.2±397.4)mm Hg/s, -dp/dtmax (1422.1±334.4) mm Hg/s vs (848.3±308.3) mm Hg/s and (849.5±278.3)mm Hg/s, P＜0.05], along with increase in both SERCA2a protein level (1.13±0.26 vs 0.73 ±0.17 and 0.64±0.18, P＜0.05) and activity [(16.2±5.5) IU/ml vs (7.9±3.1) IU/ml and (7.5 ±2.8)IU/ml, P ＜0.05] compared with HF/HF + EGFP groups. Serum concentrations of inflammatory factor tumor necrotic factor α [(382.3±114.4) ng/L vs (732.3±201.4) ng/L and (689.8±192 5) ng/L, P＜0. 05], neural-hormonal factors brain natriuretic peptide [(142.6±45.3) ng/L vs (422.3±113.6) ng/L and(393.7 ±103.3)ng/L, P＜0.01], endothelin-1 [(111.4 ±37.5)ng/L vs (193.5 ±54.3)ng/L and (201.0±72.1)ng/L,P＜0.05] and angiotensin Ⅱ[(189.7±65.2)μg/L vs (538.3 ± 135.2) μg/L and ( 525.5±144.1)μg/L, P＜0.01] were also significantly decreased in HF + SERCA2a group compared with HF/HF + EGFP groups. The apoptotic index [(12.71±4.11)% vs(23.22±7.23) % and (24.31±6.38)%, P＜0.05], protein levels of GRP78 (1.27±0.33 vs 3.23±1.14 and 4.18±1.13, P＜0.05)and protein level ratios of cleaved caspase-12 to total caspase-12[(4.62±1.93)% vs (9.71±2.70)% and (10.14±2.81)%, P＜0.05] were also significantly reduced in the ischemic myocardium of HF+SERCA2a group compared with the HF/HF + EGFP groups. Conclusion Overexpression of SERCA2a significantly improved cardiac systolic and diastolic function in this HF model partly through attenuation of ER stress related myocardial apoptosis, suggesting its therapeutic potential for CM1 related heart failure.     

培哚普利对心衰大鼠心肌SR Ca2+释放通道密度和mRNA表达的影响

目的 :探讨培哚普利对慢性心衰心肌肌浆网 （SR） Ca2 +释放通道 （Ry R2 ）密度和 m RNA表达的影响及意义。方法 :通过结扎大鼠左冠脉建立慢性心衰模型 ,以培哚普利进行干预 ,对照观察血流动力学、[3 H ]- ryanodine与左室心肌 Ry R2 最大结合量 （Bmax）和 Kd 值、Ry R2 m RNA表达水平。结果 :心衰组 （F组 ）与对照组 （C组 ）相比 ,L VEDP显著升高 （P<0 .0 1） ,+dp/dtmax,- dp/dtmax显著低于 C组 （P<0 .0 1）。F组 [3 H]- ryanodine与 Ry R2 最大结合量 Bmax显著低于 C组 （P<0 .0 1） ,P组显著高于 F组 （P<0 .0 1） ,3组 Kd 值无显著差异 （P>0 .0 5 ） ;F组 Ry R2 m RNA表达水平显著低于 C组 （P<0 .0 1） ,P组显著高于 F组 （P<0 .0 1）。结论 :培哚普利长期干预慢性心衰 ,能够增加 Ry R2基因表达 ,增加 Ry R2 密度 ,可能与其改善心肌收缩功能有关     

过表达肌浆网钙ATP酶治疗实验性慢性缺血性心力衰竭

Objective Chronic myocardial ischemia (CMI) has become the most importat cause of heart failure (HF) all over the world. The aim of the current study was to investigate the effects of Sarcoendoplasmic reticulum calcium ATPaee 2a (SERCA2a) gene transfer on cardiac function and endoplasmic reticulum stress (ERS) associated myocardial apoptosis in a minipig HF animal model induced by CMI. Methods HF was induced in minipigs by implantation of ameroid constrictor in the initial segment of left anterior descending (LAD) branch of coronary artery. After confirmation of myocardial perfusion defects and cardiac function impairment by myocardial perfusion imaging and echocardiography, animals were divided into 4 groups (n =4 each): HF group, HF + enhanced green fluorescent protein (EGFP) group,HF + SERCA2a group, and shamed animals as control group. A total amount of 1×1012 v.g. Of rAAV1EGFP or rAAV1-SERCA2a were injected intramyocardially to each animal of HF + EGFP and HF +SERCA2a groups. Sixty days after gene transfer, protein level and activity of SERCA2a were examined,cardiac functions and changes of serum inflammatory and neuro-hormonal factors were determined. Apoptotic index of the ischemic myocardium, protein levels of ER stress marker glucose regulated protein 78 ( GRP 78) and ER stress specific apoptotic marker caspase-12 were also assayed. Results At the study end,echocardiographic and hemodynamic measurements indicated a significant improvement of both cardiac systolic and diastolic function in HF + SERCA2a group compared with HF/HF + EGFP groups [LVEF (60.2±8.6)%vs (44.2±7.1)% and (46.8±6.7)%, Ev/Ay 1.28±0.24 vs 0.77 ±0.17 and 0.80±0.21, +dp/dtmax(2713.9 ±434.0) mm Hg/s ( 1 mm Hg =0.133 kPa) vs (1892.3 ±434.2) mm Hg/s and (1931.2±397.4)mm Hg/s, -dp/dtmax (1422.1±334.4) mm Hg/s vs (848.3±308.3) mm Hg/s and (849.5±278.3)mm Hg/s, P＜0.05], along with increase in both SERCA2a protein level (1.13±0.26 vs 0.73 ±0.17 and 0.64±0.18, P＜0.05) and activity [(16.2±5.5) IU/ml vs (7.9±3.1) IU/ml and (7.5 ±2.8)IU/ml, P ＜0.05] compared with HF/HF + EGFP groups. Serum concentrations of inflammatory factor tumor necrotic factor α [(382.3±114.4) ng/L vs (732.3±201.4) ng/L and (689.8±192 5) ng/L, P＜0. 05], neural-hormonal factors brain natriuretic peptide [(142.6±45.3) ng/L vs (422.3±113.6) ng/L and(393.7 ±103.3)ng/L, P＜0.01], endothelin-1 [(111.4 ±37.5)ng/L vs (193.5 ±54.3)ng/L and (201.0±72.1)ng/L,P＜0.05] and angiotensin Ⅱ[(189.7±65.2)μg/L vs (538.3 ± 135.2) μg/L and ( 525.5±144.1)μg/L, P＜0.01] were also significantly decreased in HF + SERCA2a group compared with HF/HF + EGFP groups. The apoptotic index [(12.71±4.11)% vs(23.22±7.23) % and (24.31±6.38)%, P＜0.05], protein levels of GRP78 (1.27±0.33 vs 3.23±1.14 and 4.18±1.13, P＜0.05)and protein level ratios of cleaved caspase-12 to total caspase-12[(4.62±1.93)% vs (9.71±2.70)% and (10.14±2.81)%, P＜0.05] were also significantly reduced in the ischemic myocardium of HF+SERCA2a group compared with the HF/HF + EGFP groups. Conclusion Overexpression of SERCA2a significantly improved cardiac systolic and diastolic function in this HF model partly through attenuation of ER stress related myocardial apoptosis, suggesting its therapeutic potential for CM1 related heart failure.     

老年大鼠心肌肌浆网功能的改变

目的 探讨老年大鼠心肌肌浆网（ＳＲ）钙转运的改变及其在心脏收缩功能障碍中的作用。方法 测定老年和成年Ｗｉｓｔａｒ大鼠心功能。取左心室肌组织制备肌浆网膜,采用Ｍｉｌｌｉｐｏｒｅ滤过法测定心肌ＳＲＣａ＾２＋摄取、Ｃａ＾２＋释放和＾３Ｈ－Ｒｙａｎｏｄｉｎｅ受体结合,并测定心肌ＳＲＣａ＾２＋－ＡＴＰ酶活性。结果 与成年组比较,老年组大鼠左室舒张末压（ＬＶＥＤＰ）升高８２％（Ｐ〈０．０５）,左室内压变化速度