【作者】 李妮妮；

【导师】 廉哲勋；

【作者基本信息】 青岛大学 ， 内科学， 2010， 硕士

【摘要】 目的观察缺血后处理(IPO)、三磷酸腺苷(ATP)和腺苷受体激动剂CGS-21680、阻断剂SCH58261药物后处理对心肌缺血再灌注损伤(MIRI)的影响,并探讨其机制。方法60只健康新西兰大白兔随机分成5组,即缺血再灌注组(I/R组)、IPO组、ATP后处理组、CGS-21680后处理组、SCH58261+IPO组(即SCH58261组),每组12只。建立兔心肌I/R模型,于再灌注末,由颈静脉取血用硫代巴比妥酸法测定丙二醛(MDA)的活性及黄嘌呤氧化酶法测定超氧化物歧化酶(SOD)的活力。采用伊文思蓝和NBT染色方法计算各组兔的心肌梗死面积。用HE染色法观察心肌组织病理形态变化。以末端脱氧核苷酸转移酶介导的dUTP末端缺口标记(TUNEL)法检测心肌细胞凋亡指数。用实时荧光定量反转录聚合酶链反应(RT-PCR)法检测各组心肌组织中凋亡基因caspase-3 mRNA和Bcl-2 mRNA的表达。结果①与I/R组和SCH58261组比较,IPO组、ATP组和CGS21680组血清MDA水平及心肌梗死面积显著降低(P＜0.05),而血清SOD的活力明显升高(P<0.01)。②TUNEL法检测结果显示,IPO组、ATP组和CGS-21680组的细胞凋亡指数,与I/R组和SCH58261组相比明显降低,心肌组织的损伤显著减轻(P＜0.01)。③与I/R组和SCH58261组比较,IPO组、ATP组和CGS-21680组caspase-3 mRNA的表达明显下调(P<0.01), Bcl-2 mRNA的表达显著上调(P<0.01)。以上检测指标,I/R组和SCH58261组2组间比较,IPO组、ATP组和CGS-21680组3组间比较差异均无统计学意义(P＞0.05)结论缺血后处理与ATP后处理均可减轻MIRI发挥保护作用。二者的保护作用与腺苷A2a受体的激活有关,其机制可能与上调Bcl-2基因和下调caspase-3基因的表达,抑制氧自由基的氧化应激损伤,减少细胞的凋亡有关。更多还原

【Abstract】 Objective To investigate the effects of ischemic postconditioning (IPO), adenosine triphosphate (ATP) and adenosine receptor agonist CGS-21680 and antagonist SCH58261 pharmacological postconditioning on myocardial ischemia reperfusion injury (MIRI), and to explore the mechanism.Methods Sixty New Zealand white rabbits were randomly divided into five groups (n=12 each):I/R group, IPO group, ATP group, CGS-21680 group and SCH58261+IPO group (SCH58261 group).The model of myocardial I/R was established. Malondialdaldehyde (MDA) and superoxide dismutase (SOD) in the five groups were evaluated at the end of 3h reperfusion. Ischemic and infarct areas were measured by Evans blue and NBT staining. The light microscope was used to observe the tissue changes of myocardium. Apoptosis was identified and quantified as apoptosis index (AI) using TUNEL method. The mRNA expression of caspase-3 and Bcl-2 in myocardial tissue was determined by real-time quantitative reverse transcriptase (RT)-polymerase chain reaction (PCR).Results Compared with those in I/R group and SCH58261 group, myocardial infarct size and the level of MDA markedly decreased in IPO group, in ATP group and CGS-21680 group (P<0.05). The levels of SOD increased significantly (P<0.01). TUNEL method showed that AI significantly decreased and the histopathological changes of the myocardium were relieved obviously in IPO group, in ATP group and CGS-21680 group compared with those in IR group and SCH58261 group (P<0.01). The results of real-time RT-PCR showed that the mRNA expression of caspase-3 was down-regulated, while Bcl-2 was up-regulated in IPO group, in ATP and CGS-21680 group (P<0.01).No significant difference was observed between I/R group and SCH58261 group, and among the three groups of IPO group, ATP group and CGS-21680 group (P>0.05).Conclusion Ischemic postconditioning and ATP postconditioning attenuate the myocardial IR injury via activation of adenosine A2a receptor. The mechanism may be associated with the up-regulation of Bcl-2 mRNA expression and the down-regulation of caspase-3 expression, which inhibits oxidation stress and decreases cell apoptosis.更多还原