摘要
目的探讨后适应不同模式对大鼠急性心肌缺血-再灌注损伤的影响，并进一步研究丝裂原活化蛋白激酶途径（MAPK）在其中的作用。方法60只SD大鼠随机（随机数字法）分为假手术组（Sham）、缺血-再灌注组（I／R）、渐进缩短后适应组（GDR，后适应处理方案短暂再灌注／缺血时间为30／10-25／15—15／25—10／30s）、标准后适应组（ER，后适应处理方案为20／20s×4）和渐进延长后适应组（GIR，后适应处理方案短暂再灌注／缺血时间为10／30—15／25-25／15—30／10s）5组，建立急性心肌梗死和缺血后适应模型。再灌注6h后每组取3只处死，取心肌组织用Western Blot方法测定磷酸化细胞外信号调节蛋白激酶（P-ERK）、磷酸化应激活化蛋白激酶（stress activated protein kinase，P-JNK）、磷酸化p38 MAPK（P—p38）、肿瘤坏死因子-α（TNF-α）、半胱氨酸天冬氨酸蛋白酶-8（Caspase-8）在心肌组织中的表达及细胞色素c在胞浆中的表达；各组其余大鼠再灌注24h后测定血流动力学，抽血测心肌酶，取心脏进行TUNEL凋亡检测。统计学多组间比较应用单因素方差分析，组间差异两两比较应用q检验。结果三种后适应处理组均有显著的心肌保护作用（P〈0．05），其中GIR组最为明显，其次是ER组，GDR组最不明显。GIR组同ER组相比，细胞凋亡指数和血清标志物水平更低；P—ERK表达水平高于ER组[（1．82±0．22）vs．（1．54±0．32），P〈0．05]，同时P-p38[（0．82±0．26）vs．（1．63±0．24）]，P-JNK[（0．76±0．28）vs．（1．33±0．21），TNF-α[（0．62±0．20）vs．（1．00±0．12）]，Caspase-8[（0．61±0．21）vs．（1．004±0．30）]，Cyt—c[（0．66±0．16）vs．（1．68±0．22）]表达水平低（以上P〈0．05）。在以上指标中渐进延长后适应组均显著优于渐进缩短后适应组。结论渐进延长后适应较标准后适应能显著减轻心肌再灌注损伤，MAPK途径在其中发挥了重要作用。
Objective To aims Study cardioproteetion of different posteonditioning algorithm, and investigate the role of MAPK pathway in the process. Methods Sixty SD rats were randomly （random number） divided into 5 groups, sham operation group, reperfusion/injury group （I/R group）, gradual decreased reperfusion in postconditioning （ GDR, 30/10 - 25/15 - 15/25 - 10/30s of reperfusion/re - occlusion） group, routine reperfusion in postconditioning （ER, 4 cycles of 20/20s of reperfusion/reocclusion） group, and gradual increased reperfusion in postconditioning （ GIR, 10/30 - 15/25 - 25/15 - 30/10s of reperfusion/re-ocelusion ） group. Acute myocardial infarction and ischemic postconditioning models were established in the rats. Six hours after reperfusion, 3 rats of each group were sacrificed andmyocardial tissue were taken out to measure the level of phosphorylation of extracellular signal regulated protein kinase （P-ERK）, Phosphorylation of stress-activated protein kinase （stress activated protein kinase, P-JNK） , phosphorylation of p38 MAPK （P-p38）, tumor necrosis factor -α （TNF -α）, cysteine and aspartic protease -8 （ Caspase-8 ） in myocardial tissue and the expression of cytochrome C in the cytosol using Western Blot method. Twenty-four hours after reperfusion all the remaining rats were to measure hemodynamie variables and level of myocardial enzyme, and myocardial tissue were taken out to determine myocardial apoptosis. A one-way analysis of variance （ANOVA） was used, and q tests were employed to determine differences in individual variables existed between groups. Results All three postconditioning modalities were found to provide cardioprotection （ P 〈 0. 05 ） compared with I/R without preconditioning. The GIR provided the best cardioprotection effect, followed by ER and then GDR. Apoptotic index and serum marker levels were reduced far more in GIR than those in ER （ P 〈 0. 05 ）. The enhanced cardioprotection provided by GIR was accompanied by significantly increased levels of P-ERK1/2 [ （ 1.82 ± 0.22 ） vs. （1.54＋0.32）, P〈0.05], and lower levels of P-p38 [ （0.82 ±0.26） vs. （1.63 ± 0.24）1, P-JNK [ （0.76±0.28） vs. （1.33±0.21）, TNF-α [ （0.62±0.20） vs. （1.00±0.12）], Caspase-8 [ （0.61 ±0.21） vs. （1.00±0.30）], Cyt-c [ （0.66±0. 16） vs. （1.68 ±0.22）] in the cytoplasm （P 〈 0.05, all compared with ER ）. In addition, all the variables measured here were significantly improved in the GIR group relative to the GDR group （P 〈 0.05 ）. Conclusions The method of gradual increased reperfusion in posteonditioning eould attenuate reperfusion injury more signifieantly than routine algorithm whereby MAPK pathway played an important role in the process.
出处
《中华急诊医学杂志》
CAS
CSCD
北大核心
2013年第8期859-865,共7页
Chinese Journal of Emergency Medicine
基金
基金项目：国家自然科学基金（30740080）
济南军区总医院院长青年基金（2011Q08）
关键词
后适应
渐进延长
缺血-再灌注损伤
急性心肌梗死
丝裂原活化蛋白激酶
凋亡
细胞色素C
肿瘤坏死因子Α
Postconditioning
Gradual increase
Ischemic reperfusion injury
Acute myocardialinfarction
Mitogen activated protein kinase （MAPK）
Apoptosis
Cytochrome C
Tumor necrosis factort~
