七氟醚后处理减轻大鼠心肌缺血-再灌注损伤

目的分析七氟醚后处理对大鼠心肌缺血-再灌注损伤的影响并探讨其机制。方法清洁级成年雄性SD大鼠72只,3月龄,体重180～230 g。采用随机数字表法分为四组:假手术组(S组)、单纯七氟醚组(Sev组)、缺血-再灌注组(IR组)和七氟醚后处理组(SP组),每组18只。S组:穿线不阻断左冠状动脉前降支(LAD);Sev组:穿线不阻断LAD,穿线稳定后60 min吸入2.4%七氟醚15 min; IR组:穿线稳定后30 min阻断LAD,缺血30 min,再灌注2 h; SP组:穿线稳定后30 min阻断LAD,缺血30 min,再灌注2 h,同时在穿线稳定后60 min吸入2.4%七氟醚15 min。于再灌注后2 h,采用ELISA法检测血清LDH浓度,Western Blot法检测心肌受体相互作用蛋白1(RIPK1)、p-RIPK1、受体相互作用蛋白3(RIPK3)、p-RIPK3、混合系激酶结构域样蛋白(MLKL)、p-MLKL含量,荧光显微镜观察程序性坏死心肌细胞的荧光强度,1%氯化三苯基四氮唑(TTC)染色法检测心肌梗死面积百分比,HE染色后光镜下观察心肌病理学形态。结果与S组比较,IR组和SP组血清LDH浓度明显升高(P0.05),心肌RIPK1、p-RIPK1、RIPK3、p-RIPK3、MLKL、p-MLKL含量明显增加(P0.05),程序性坏死心肌细胞荧光强度明显增强(P0.05),心肌梗死面积百分比明显升高(P0.05),心肌细胞排列更为紊乱。与IR组比较,SP组血清LDH浓度明显降低(P0.05),心肌RIPK3、p-RIPK3、MLKL和p-MLKL含量明显减少(P0.05),程序性坏死心肌细胞荧光强度明显减弱(P0.05),心肌梗死面积百分比明显降低(P0.05),心肌细胞排列更为整齐。S组和Sev组间各指标差异无统计学意义。结论七氟醚后处理可通过升高血清LDH浓度、降低心肌梗死面积百分比、改善心肌病理学改变减轻大鼠心肌缺血-再灌注损伤,其机制可能与抑制缺血-再灌注损伤后心肌细胞程序性坏死相关。

Effects of sevoflurane postconditioning on necroptosis during myocardial ischemia-reperfusion injury in rats

Objective To evaluate the effects of sevoflurane postconditioning on necroptosis during myocardial ischemia-reperfusion injury rats.
Methods Seventy-two adult male Sprague-Dawley rats, aged 3 months, weighing 180-230 g, were randomly divided into 4 groups: sham control group (group S), purely administration of sevoflurane group (group Sev), ischemia-reperfusion group (group IR) and sevoflurane postconditioning group (group SP), 18 rats in each group. Group S was only threading but not blocking the left anterior descending coronary artery (LAD). Group Sev was only threaded but LAD was not blocked, 2.4% sevoflurane was inhalated continued for 15 minutes after threading 60 minutes. Group IR was threaded 30 minutes, LAD ischemia was blocked for 30 minutes, and reperfusion was performed for 2 hours. Group SP was threaded 30 minutes, LAD ischemia was blocked for 30 minutes, reperfusion was performed for 2 hours, and 2.4% sevoflurane was inhalated continued for 15 minutes after threading 60 minutes. After reperfusion, the serum LDH concentration was detected by ELISA method, the expression levels of receptor interacting protein kinase 1 (RIPK1), p-RIPK1, receptor interacting protein kinase 3 (RIPK3), p-RIPK3, mixed lineage kinase domain-like protein (MLKL), and p-MLKL were measured by western blot, the fluorescence signal value of necroptosis cardiomyocyte was observed by fluorescence microscopy, myocardial infarct size was measured by 1% 2,3,5-triphenyltetrazolium chloride (TTC), and the myocardial pathological slices of rats in each group were observed under the light microscope after HE staining.
Results Compared with group S, serum LDH concentration risen (P < 0.05), the expression of RIPK1, p-RIPK1, RIPK3, p-RIPK3, MLKL, and p-MLKL was up-regulated (P < 0.05), the fluorescence intensity of necrotic myocardial cells was enhanced (P < 0.05), myocardial infarction area increased (P < 0.05) and cardiomyocytes arranged disorderly in groups IR and SP. Compared with group IR, serum LDH concentration reduced (P < 0.05), the expression of RIPK3, p-RIPK3, MLKL, and p-MLKL was down-regulated (P < 0.05), the fluorescence intensity of necrotic myocardial cells was inhibited (P < 0.05), myocardial infarction area decreased (P < 0.05) and cardiomyocytes lined up neatly in the group SP. There were no statistical differences between groups S and Sev in these indicators.
Conclusion Sevoflurane postconditioning could reduce myocardial ischemia-reperfusion injury in rats, improve hemodynamics, cardiac function indicators and myocardial pathology changes, and its mechanism relates to necroptosis.