异氟醚预处理延迟相对兔心肌缺血-再灌注损伤核因子-κB的影响

目的 探讨异氟醚预处理延迟相对心肌缺血-再灌注损伤的保护机制.方法 雄性新西兰兔30只,体质量2.0～2.5 ks.随机分成3组(n=10):假手术组(C组)、缺血再灌注组(I/R组)、2.0%异氟醚预处理组(S组).C组吸入100%氧气2 h,24 h后仅行左冠脉套线而不阻断160 min,I/R组吸入100%氧气2 h,24 h后行左冠状动脉前降支阻断40 min,再灌注120 min;S组吸入2.0%异氟醚+100%氧气2 h,24 h后处理同I/R组.各组分别于左冠前降支阻断前20 min(TI)、左冠前降支阻断20 min(T2)、左冠前降支阻断40 min(T3)、心肌再灌注1 h(T4)、心肌冉灌注2 h(T5)五个时点抽取颈内动脉血ELISA法测血清IL-10和TNF-α水平.再灌注结束后观察心肌细胞超微结构的变化,免疫印记法测心肌核因子-κB(NF-κB)活性水平,同时用伊文思蓝和TTC染色法测心梗面积.计量资料采用均数±标准差(x±s)表示,用SPSS 13.0统计学软件进行分析,组间采用方差分析,以P<0.05为差异具有统计学意义.结果 与I/R组比,S组IL-10明显升高(P<0.05),TNF-α明显降低(P<0.05),NF-κB表达降低(P<0.05),心肌梗死面积减少(P<0.05).结论 异氟醚预处理延迟相通过抑制心肌NF-κB的活性,调控炎性细胞因子平衡来减轻心肌缺血-再灌注损伤发挥保护作用.

Effects of isoflurane delayed preconditioning on nuclear factor-κB during myocardial ischemia reperfusion injury in rabbits

Objective To explore the mechanism of the catdioprotection of isoflurane delayed preconditioning on myocardial ischemia reperfusion injury in rabbits.Method Thirty male New Zealand white rabbits,weighing 2.0 to 2.5 kg,were randomly divided into three groups(ten for each group):Control group(group C),I/R group(I/R group) ,2.0% isoflurane group(group S) .Group S was exposed to 2.0% isoflurane-100% oxygen for2 h.Group C and I/R group were exposed 2 h to 100% oxygen served as untreated controls.Twenty-four hours later I/R group and group S underwent 40 rain of coronary occlusion followed by 2 h of reperfusion.Blood samples were taken from arterial line at 20 min before occlusion(T1) ,20 rain after occlusion(T2) ,40 rain after occlusion(T3) ,1 h after reperfusion(T4) and 2 h after reperfusion(TS) for determination of plasma IL-10 levels and TNF-alevels by ELISA.At the end of the reperfusion,infarct size and area at risk were defined by Evans and TTC staining.The heart was harvested and levels of the nuclear factor kappa β(NF-κB)activity were determined by Western Blot,and ultrastructures were observed by electron microscopy.The data was expressed as,and were analyzed by using oneway ANOVA test with SPSS 13.0.P value less than 0.05 indicated statistical significance.Results The NF-κB activity of group S was significantly lower than that of group I/R(P<0.05).Group S significantly(P<0.05)reduced infarct size(19.7%±2.8% in group S) of the left ventricular area at risk as compared with control (37.8 %±1.7 % in I/R group).The injury of I/R group was worse than that of group S from the changes of the cellular structure under light microscope.Group S had a lower levels of TNF-α and also had a higher level of IL-10.Conclusions Isoflurane can inhibit NF-κB activity during myocardial ischemia reperfusion and modulate the cytokine expression,which may be one of molecular mechanisms of Isoflurane delayed preconditioning on cardioprotection.