七氟醚预处理早期对大鼠心肌缺血再灌注心肌细胞自噬的影响

The effect of early sevoflurane preconditioning on autophagy during myocardial ischemia reperfusion in rats

目的探讨七氟醚预处理早期对大鼠心肌缺血再灌注心肌保护作用及对心肌细胞自噬的影响。方法清洁级雄性SD大鼠45只,8~12周龄,体质量200~240 g。随机分为假手术组(Sham组,n=15)、缺血再灌注组(I/R组,n=15)和七氟醚预处理组(Sevo组,n=15)。采用冠脉阻断30 min再灌注120 min的方法制备大鼠心肌缺血再灌注损伤模型。Sevo组于缺血前30 min行七氟醚预处理:吸入2.5%七氟醚15 min,洗脱15 min。随后结扎左前降支,阻断冠脉血流30 min后,解除阻断再灌注120 min。再灌注120 min时测定肌钙蛋白I(c Tn I)和肌酸激酶同工酶(CK-MB)的浓度、心肌梗死面积、LC3-Ⅱ和Beclin-1的蛋白表达情况。结果与Sham组比较,I/R组心肌c Tn I和CK-MB浓度升高,心肌梗死面积增加,LC3-Ⅱ和Beclin-1蛋白表达上调(P<0.05);与I/R组比较,Sevo组心肌c Tn I和CK-MB浓度降低,心肌梗死面积减少(P<0.05),LC3-Ⅱ和Beclin-1蛋白表达差异无统计学意义(P>0.05)。结论七氟醚预处理早期能减轻心肌缺血再灌注损伤,但是七氟醚预处理早期未显著影响心肌细胞自噬水平。

Objective To investigate the protective effect of sevoflurane preconditioning on myocardial ischemia reperfusion injury in rats and its effect on autophagy in myocardial cells.Methods Forty-five healthy male Sprague-Dawley rats,aged8-12weeks,weighing200-240g,were divided into3groups(n=15)randomly:sham operation group(Sham group),ischemia reperfusion group(I/R group),sevoflurane preconditioning group(Sevo group).The hearts of rats were subjected to30min of global ischemia followed by120min of reperfusion to establish the model of myocardial I/R injury.Sevo group inhaled2.5%sevoflurane for15min and15min washed out,totally30min before myocardial ischemic-reperfusion.At120min of reperfusion,the concentration of cardiac tropine I(cTnI)and creatine kinase-MB(CK-MB)were detected by ELLISA.The rats were then sacrificed,and hearts were removed for determination of heart infarct size and expression of microtubule-associated protein1light chain3-Ⅱ(LC3-Ⅱ)and Beclin-1(by Western blot).Results Compared with group Sham,the concentration of cTnI and CK-MB in group I/R and group Sevo were increased significantly,myocardial infarction area was increased,and the expression of LC3-Ⅱand Beclin-1were up-regulated(P<0.05).Compared with the I/R group,the concentration of cTnI and CK-MB in Sevo group were significantly decreased,the myocardial infarction area decreased(P<0.05).Compared with the group I/R,there was no significant difference in the expression of LC3-Ⅱand Beclin-1in Sevo group(P>0.05).Conclusion Sevoflurane preconditioning can attenuate myocardial ischemia and reperfusion injury at early stage,but sevoflurane preconditioning does not significantly affect autophagy level in the early stage of myocardial ischemia.