线粒体乙醛脱氢酶2在心肌保护中的作用及可能机制探讨

发布时间：2018-11-14 13:45

【摘要】：目的：研究ALDH2对离体大鼠心肌缺血/复灌损伤的作用，进一步探讨ALDH2心肌保护作用是否与体内一氧化氮的生成有关，并分析线粒体通透性转换孔是否参与其中。方法：实验大鼠随机分为缺血/复灌组(Ischemia and Reperfusion, I/R)、酒精(ethanol, EtOH)干预组(I/R+EtOH)、氨基氰（cyanamide, CYA）干预组（I/R+CYA）及酒精+氨基氰干预组(I/R+EtOH+CYA)；硝基L-精氨酸甲基酯(NG-nitro-L-methyl arginine ester,L-NAME)干预组（I/R+L-NAME）及酒精+硝基L-精氨酸甲基酯干预组（I/R+EtOH+L-NAME）；酒精+苍术苷(Atractyloside,Atr)干预组(I/R+EtOH+Atr)。采用离体大鼠心脏Langendorff灌流方法,结扎冠状动脉左前降支30min和复灌120min复制局部缺血/复灌损伤模型,测定左室心功能指标；测量冠脉流出液中乳酸脱氢酶(lactatede hydrogenase，LDH)含量及心肌组织一氧化氮（nitric oxide, NO）含量； TTC双染法测定心肌梗死面积； RT-PCR技术检测心肌组织中ALDH2、Bcl-2、Bax的基因表达。结果：1.左室心功能指标：I/R组缺血后左室发展压（left ventricular developed pressure, LVDP）、左室内压最大上升速率/下降速率（±dp/dtmax）、左心室做功（rate pressure product, RPP）下降，心率（heart rate, HR）稍下降，左室舒张末压（left ventricular end diastolic pressure,LVEDP）抬高，复灌末LVDP、±dp/dtmax、HR和RPP均下降明显，LVEDP明显抬高。与I/R组相比，EtOH组抑制了LVDP、HR、±dp/dtmax及RPP的下降并抑制了LVEDP的抬高（P0.05~P0.01）；CYA组促进了复灌期LVDP、±dp/dtmax、RPP的下降并抬高了LVEDP（P0.05~P0.01）；EtOH+CYA组、EtOH+L-NAME及EtOH+Atr组的结果与CYA组类似（P0.05~P0.01）。2.冠脉流出液中LDH含量：与I/R组相比，EtOH组、EtOH+L-NAME组明显降低了复灌初期冠脉流出液中LDH的释放（P0.01）；CYA组和EtOH+CYA组明显增加了LDH的释放(P0.01)。与EtOH组相比，EtOH+CYA组、EtOH+Atr组明显增加了LDH的释放(P0.01)；EtOH+L-NAME组在复灌5min时明显增加了冠脉流出液中LDH的释放(P0.01)。3.心肌梗死面积：与I/R组相比，，EtOH组降低了心肌梗死面积（P0.05）；CYA组、EtOH+CYA组及EtOH+Atr组明显增加了心肌梗死面积(P0.01)。与EtOH组相比，EtOH+CYA组、EtOH+L-NAME组、EtOH+Atr组均明显增加了心肌梗死面积(P0.01)。4.心肌组织中的NO量：与I/R组相比，EtOH组、L-NAME组及EtOH+L-NAME组均明显降低了心肌组织中的NO含量(P0.01)。与EtOH组相比，EtOH+L-NAME组进一步降低了NO的释放。5.RT-PCR：与I/R组相比，EtOH组心肌组织中ALDH2、Bcl-2表达显著增高（P0.01），Bax表达显著降低（P0.01）；CYA组和EtOH+CYA组ALDH2、Bcl-2表达显著降低（P0.05~P0.01），Bax表达显著增高（P0.05）；EtOH+Atr组ALDH2、Bcl-2表达显著降低（P0.01），Bax差异无显著性（P0.05）。与EtOH组相比，EtOH+CYA组、EtOH+L-NAME组、EtOH+Atr组ALDH2、Bcl-2表达显著降低（P0.01），Bax表达显著增高（P0.01）。结论：ALDH2活性增高起到保护心肌和抗凋亡的作用，ALDH2活性降低加重了心肌损伤，促进心肌凋亡。ALDH2心肌保护机制可能与降低缺血/复灌心肌组织中的NO有关； ALDH2可抑制线粒体渗透性转换孔道的开放。
[Abstract]:Aim: to study the effects of ALDH2 on myocardial ischemia / reperfusion injury in isolated rats and to explore whether the myocardial protective effect of ALDH2 is related to the production of nitric oxide in vivo and whether the mitochondrial permeability transition pore is involved in it. Methods: experimental rats were randomly divided into ischemia / reperfusion group (Ischemia and Reperfusion, I / R) and alcohol (ethanol, EtOH) intervention group (I / R EtOH), cyanamide,). CYA (I / R CYA) and I / R EtOH CYA); (I / R EtOH CYA);) Nitro L-arginine methyl ester (NG-nitro-L-methyl arginine ester,L-NAME) intervention group (I / R L-NAME) and alcohol nitro-L-arginine methyl ester intervention group (I / R EtOH L-NAME); Alcohol Atractyloside (Atractyloside,Atr) intervention group (I / R EtOH Atr).) The left ventricular cardiac function was measured by ligating the left anterior descending coronary artery (30min) and reperfusion (120min) by Langendorff perfusion in isolated rat heart. The contents of lactate dehydrogenase (lactatede hydrogenase,LDH) and nitric oxide (nitric oxide, NO) in myocardial tissue were measured, the myocardial infarction area was measured by TTC double staining, and the gene expression of ALDH2,Bcl-2,Bax in myocardial tissue was detected by RT-PCR technique. Results: 1. Left ventricular function index: left ventricular development pressure (left ventricular developed pressure, LVDP), left ventricular pressure (rate pressure product, RPP) and heart rate (heart rate, HR) decreased in I / R group after ischemia. Left ventricular end-diastolic pressure (left ventricular end diastolic pressure,LVEDP) elevated, LVDP, 卤dp/dtmax,HR and RPP decreased significantly and LVEDP increased significantly at the end of reperfusion. Compared with I / R group, EtOH group inhibited the decrease of LVDP,HR, 卤dp/dtmax and RPP and the elevation of LVEDP (P0.05~P0.01); CYA group promoted the decrease of LVDP, 卤dp/dtmax,RPP and LVEDP (P0.05~P0.01); The results of EtOH CYA group, EtOH L-NAME group and EtOH Atr group were similar to that of CYA group (P0.05~P0.01). 2. LDH content in coronary effluents: compared with I / R group, EtOH group and EtOH L-NAME group significantly decreased the release of LDH in coronary effluents (P0.01); CYA group and EtOH CYA group significantly increased LDH release (P0.01). Compared with EtOH group, EtOH Atr group in, EtOH CYA group significantly increased the release of LDH (P0.01); EtOH L-NAME group significantly increased LDH release in coronary effluents during 5min reperfusion (P0.01). Myocardial infarction area: compared with I / R group, EtOH group decreased myocardial infarction area (P0.05); CYA group, EtOH CYA group and EtOH Atr group significantly increased myocardial infarction area (P0.01). Compared with EtOH group, EtOH Atr group in EtOH L-NAME group increased myocardial infarction area significantly (P0.01). The amount of NO in myocardial tissue: compared with I / R group, EtOH group, L-NAME group and EtOH L-NAME group significantly decreased the content of NO in myocardial tissue (P0.01). Compared with EtOH group, EtOH L-NAME group further decreased the release of NO. 5. RT-PCR: compared with I / R group, the expression of ALDH2,Bcl-2 in myocardial tissue of EtOH group was significantly higher (P0.01), Bax expression was significantly lower (P0.01); ALDH2,Bcl-2 expression in CYA group and EtOH CYA group was significantly decreased (P0.05~P0.01), Bax expression was significantly increased (P0.05) ALDH2,Bcl-2 expression in); EtOH Atr group was significantly decreased (P0.01), Bax was not significantly different (P0.05). Compared with EtOH group, the expression of ALDH2,Bcl-2 in, EtOH Atr group of EtOH L-NAME group was significantly lower than that in, EtOH CYA group (P0.01), Bax expression was significantly higher (P0.01). Conclusion: the increase of ALDH2 activity can protect myocardium and inhibit apoptosis, and the decrease of ALDH2 activity can aggravate myocardial injury and promote myocardial apoptosis. The mechanism of myocardial protection of ALDH2 may be related to the reduction of NO in ischemic / reperfusion myocardium. ALDH2 inhibited the opening of mitochondrial permeability transition channels.
【学位授予单位】：蚌埠医学院
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R363

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