缺血预适应对大鼠肺缺血再灌注中NF-κB表达的影响

The effects of ischemic preconditioning on the expression of NF-κB in lung after ischemia-reperfusion injury

目的研究缺血预适应(IP)对缺血再灌注(I/R)后在体鼠肺脏NFκB表达的影响,探讨IP减轻肺脏I/R损伤的可能机制及NFκB的作用。方法雄性SD大鼠36只,随机分为3组假手术(Sham)组,缺血再灌注(I/R)组,缺血预适应(IP)组。I/R组开胸后,建立在体肺脏I/R损伤模型。在此基础上,IP组于缺血开始前,应用3个循环的5min缺血+5min灌注进行IP处理。用免疫组化法观察肺脏NFκB的表达,同时测定肺脏湿重/干重(W/D)比值,电镜下观察肺脏超微结构的改变,光镜下HE染色观察肺脏的病理形态学变化。结果IP组和I/R组相比肺脏NFκB表达有显著性差异(P<0.01),肺脏超微结构损害和肺水肿程度明显减轻。结论IP可抑制I/R损伤时肺组织中NFκB的表达,从而减轻肺脏超微结构损害和肺水肿程度,减轻肺I/R损伤。

Objective To investigate the effects of ischemic preconditioning on the expression of nuclear factor-κB(NF-κB) in lung after lung ischemia-reperfusion (I/R) in rats and to study the possible role of ischemic preconditioning in the mechanism of attenuating I/R injury. Methods Thirty-six male Sprague-Dawley rats were randomized into three groups (twelve for sham operation ,twelve for ischemia-reperfusion, twelve for ischemic preconditioning ).I/R injury consisted of 45 minutes of lung cross-clamping followed by 2 hours (or 5 hours )of reperfusion ; for ischemic preconditioning three cycles of 5 minutes of ischemia and 5 minutes of reperfusion were applied immediately preceding I/R; sham operation animals had a thoracotomy only. Lung tissue wet-to-dry weight ratio (W/D), Expression of NF-κB in lung was observed by immunohistochemical stain and image analysis . The pathological change of lung tissue was observed under light microscopy. Electron microscopic evaluation was done on randomly selected lungs of two rats in each group at the end of the experiment. Results Expression of NF-κB decreased significantly after ischemic preconditioning (P<0.01). Conclusions Ischemic preconditioning can inhibit the expression of NF-κB after I/R injury, and attenuate ultrastructure injury of lung tissue, then relieve pulmonary edema, and protect lung from ischemia-reperfusion injury.