p38MAPK信号途径抑制剂对缺血再灌注损伤大鼠心肌细胞中MAPK通路的调控

Regulation of p38 lightning MAPK specific inhibitor in MAPK pathways in ischemia-reperfusion injury of myocardial cells

目的：探讨p38MAPK特异性抑制剂SB203580（SB）对缺血再灌注损伤心肌细胞的保护作用及对凋亡信号通路的影响。方法：选择45只250~300g雄性SD大鼠,通过阻断其左冠状动脉（冠脉）前降支（LAD）30min再灌注180min制备I/R损伤模型,随机分为3组（每组15只）：溶剂对照组（Vehicle组）、低剂量SB预处理组（SB-L组）和高剂量SB预处理组（SB-H组）。同时选取15只同周龄SD大鼠仅穿线但不结扎（Sham组）。SB-L组和SB-H组分别于LAD结扎前30min注射50、100μg/kg SB,其余两组注射等体积的0.9%氯化钠溶液。分别在术前（T0）、缺血30min后（T1）、再灌注60min（T2）、120min（T3）及180min后（T4）检测各组血浆肿瘤坏死因子（TNF）-a水平,处死大鼠并通过TTC染色分析缺血程度和梗死程度,将心脏组织包埋并采用免疫组织化学技术切片染色方法检测心肌组织中细胞外信号调节激酶（extracellular signal-regulated kinase ERK）和C-Jun氨基末端激酶（C-Jun N-terminal kinase JNK）及凋亡细胞的表达。结果：与Sham组相比,Vehicle组除T0外的I/R其余时间点的TNF-a水平均升高（均P〈0.05）;SB处理后可减轻TNF-a的升高且改善心肌缺血及梗死程度,ERK表达较Vehicle组增强,JNK表达较Vehicle组减弱（均P〈0.05）,SB-H组的改善效果优于SB-L组（P〈0.05）。结论：SB对心肌I/R损伤有改善作用,可降低心肌缺血及梗死程度,并促进ERK信号通路表达,抑制JNK信号通路的活化,抑制心肌细胞的凋亡。

Objective：To discuss p38 lightning MAPK specific inhibitor SB203580 （SB） on ischemia-reperfu- sion iniury of myocardial cells and the protective effects of apoptosis signaling pathways. Method： All 45 male 250 -300 g SD rats, by blocking the left anterior descending coronary artery （LAD） and 30 min reperfusion damage model of I/R prepared by 180 min, were randomly divided into 3 groups （n= 15） ： control group （Vehicle group）, low dose of SB pretreatment group （SB-L group） and high dose of SB pretreatment group （group SB-H）. Other 15 male SD rats were only but not occluded （Sham group）. SB-L group and SB-H group respectively iniected 50, 100 μg/kg SB before 30 min of LAD ligation, the other two groups injected 0.90/00 NaCl solution. The plasma tumor necrosis factor TNF-a level was detected respectively before operation （TO）, 30 min after ischemia reperfu- sion （T1）, 60 min （T2）, 120 min （T3） and 180 min （T4） after I/R. Ischemia and infarction degree were tested by TTC staining. The expression of cardiac tissue embedding and ERK kinase and JNK protein and apoptosis cells were analysed by immunohistochemistry staining slice method. Result：Compared to the Sham group, the levels of TNF-α in Vehicle group at all time points except TO were increased （all P〈0.05）. The intervention of SB reduced TNF-α rising and improved the degree of myocardial ischemia and infarction change, expression of ERK enhanced compared with Vehicle group, and expression of JNK weakened compared with Vehicle group （all P〈0.05）. The improvement was better in SB-H group than that in SB-L group （P〈0.05）. Conelusion：SB can improve the myo- cardial I/R injury, reduce the degree of myocardial ischemia and infarction, promote the expression of ERK signa- ling pathway, inhibit activation of JNK signaling pathway and apoptosis of myocardial cells.