福辛普利钠预处理对缺血后适应大鼠心肌组织Toll样受体表达及炎症因子的影响

大鼠预先灌胃福辛普利钠, 观察其和缺血后适应(ischemic postconditioning, IPoC)对大鼠心肌缺血再灌注(ischemic reperfusion, I/R)损伤后心肌组织Toll样受体(toll-like receptor, TLR)表达及心肌组织炎症浸润的影响. 将60只SD (Spragu-Dawley)大鼠随机分为假手术组、I/R组、IPoC组以及福辛普利钠+IPoC组, 每组15只. 假手术组大鼠心脏前降支下置线不结扎; I/R组予以心脏前降支结扎30 min, 再灌注1 h; IPoC组给予心脏前降支结扎30 min, 后予以3次10 s的再灌注/缺血循环, 再持续灌注1 h; 福辛普利钠+IPoC组则预先给予福辛普利钠片0.9 mg/kg, 连续灌胃14 d, 于末次灌胃2 h后, 施以IPoC组的干预过程. 所有实验大鼠腹主动脉取血并分离出心脏组织. 比色法测定血清肌钙蛋白T (cardiac troponin T, cTNT)的含量, NBT染色测定大鼠左室心肌梗死面积, 酶联免疫吸附测定法测定心肌组织单核细胞趋化蛋白-1 (monocyte chemotactic protein-1, MCP-1)和肿瘤坏死因子-α (tumor necrosis factor-α, TNF-α)水平. 免疫组织化学方法测定心肌组织TLR2及TLR4的表达, HE染色观察心肌组织炎性细胞的浸润. 结果表明, 与I/R组比较, IPoC组大鼠心肌梗死面积明显缩小(P<0.01), 大鼠血清cTNT水平显著降低(P<0.01), 心肌组织MCP-1, TNF-α含量和炎性细胞浸润数量明显下降(P<0.05, P<0.01), 心肌组织TLR2及TLR4的表达被显著抑制(P<0.01); 与IPoC组比较, 福辛普利钠预处理可进一步降低IPoC大鼠心肌梗死面积(P<0.05), 心肌组织TNF-?水平也显著降低(P<0.01), 对心肌TLR2及TLR4的表达有进一步抑制(P<0.05). 血管紧张素转化酶抑制剂福辛普利钠预处理可加强IPoC对I/R大鼠心肌的保护作用, 其机理可能与抑制TLR介导的炎症信号通路和趋化因子反应有关.

Effect of fosinopril sodium pretreatment on toll-like receptor and inflammatory factor in rat myocardium with ischemic postconditioning

To observe the effects of ischemic post-conditioning (IPoC) on Toll-like receptor expression and myocardial inflammatory infiltration in myocardial tissue of rats with ischemic reperfusion (I/R) injury and fosinopril sodium pre-treatment, a total of 60 Sprague-Dawley rats were randomly assigned to the following groups: sham (suture around left anterior descending coronary artery was not tied), ischemic reperfusion (30 min in situ transient occlusion of the left anterior descending artery, followed by 1 h reperfusion), IPoC (30-min occlusion of left anterior descending artery, followed by three cycles of 10-s reperfusion/10-s ischemia prior to 1-h reperfusion), and fosinopril sodium +IPoC (fosinopril sodium pre-treatment, 0.9 mg/kg, for 14 d, followed by 2-h I/R after last gavage, and IPoC treatment during I/R). Arterial blood and heart samples were extracted after 1-h reperfusion. Serum cTnT levels were measured using the colorimetric method, myocardial infarct size was measured using nitrotetrazolium blue/chloride staining, TNF-α and MCP-1 levels in myocardial tissue were measured by ELISA. TLR2 and TLR4 expression in myocardial tissue was analyzed using immunohistochemistry, and infiltrating cells were detected by hematoxylin-eosin staining. Compared with the I/R group, myocardial enzyme cTnT levels and infarct size significantly decreased in the IPoC group (P < 0.01). In addition, MCP-1 and TNF-α levels, as well as the number of infiltrating cells in myocardial tissue, significantly decreased (P < 0.05, P < 0.01, respectively). TLR2 and 4 expressions also significantly decreased in the IPoC group (P < 0.05, P < 0.01, respectively). Compared with the IPoC group, the combination of fosinopril sodium and IPoC further reduced infarct size (P < 0.05), as well as TNF-α levels in myocardial tissue (P < 0.01). TLR2 and 4 expressions and infiltration of inflammatory cells were also significantly decreased (P < 0.05). Therefore, fosinopril sodium enhanced the protective effect of IPoC in a rat model of myocardial I/R injury. These mechanisms could be related to inhibition of the TLR signal pathway and chemotactic factor reactions.