国际麻醉学与复苏杂志   2014, Issue (12): 2-2
    
七氟烷预处理联合后处理对大鼠肺缺血/再灌注损伤血管紧张素转化酶mRNA表达的影响
徐桂萍, 杜宁, 刘备1()
1.新疆维吾尔自治区人民医院麻醉科
Research of sevoflurane preconditioning combined with postconditioning on expression of angiotensin converting enzyme mRNA during lung ischemia/reperfusion in rats
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摘要:

目的 评价七氟烷预处理联合后处理对大鼠肺缺血/再灌注损伤(ischemia/reperfusion injury, I/RI)时肺组织血管紧张素转化酶(angiotensin converting enzyme, ACE)mRNA表达的影响。 方法 SD大鼠54只,采用随机数字表法将其分为3组,每组18只:假手术组(S组),仅游离大鼠左肺门,但不阻断;肺缺血/再灌注(ischemia/reperfusion, I/R)组(I/R组),采用阻断大鼠左肺门45 min后再灌注120 min的方法制备鼠肺I/R模型;七氟烷预处理联合后处理组(Spr+o组),吸入2.1%七氟烷30 min,洗脱10 min,阻断左肺门45 min后,在恢复灌注同时吸入2.1%七氟烷30 min。于再灌注30、60 min和120 min时各组随机取6只大鼠处死,取其肺组织测湿/干重比(wet-to-dry weight ratio, W/D), 苏木精-伊红(hematoxylin-eosin staining, HE)染色法行组织学检查,比色法测定丙二醛(malondialdehyde, MDA)表达水平,酶联免疫吸附法(enzyme-linked immunosorbent assay, ELISA)测定血浆内皮素-1(endothelin-1, ET-1)表达水平, 反转录酶-聚合酶链锁反应(reverse transcription-polymerase chain reaction, RT-PCR)法测定ACE mRNA的表达。 结果 与S组比较,Spr+o组和I/R组再灌注各时点肺组织W/D、ACEmRNA及血浆ET-1、MDA表达水平均升高(P<0.05)。与I/R组比较,Spr+o组在再灌注30、60、120 min肺组织W/D明显下降[(4.74±0.14) vs (5.01±0.05),(4.96±0.07) vs (5.18±0.10),(5.31±0.11) vs (5.53±0.20)](P<0.05);肺组织ACE mRNA表达水平在再灌注30、60、120 min均明显下降[(0.49±0.08) vs (0.70±0.09),(0.66±0.05) vs (0.82±0.07),(0.77±0.04) vs (0.92±0.04)](P<0.05);血浆ET-1在各再灌注时点表达水平均下降(P<0.05),以再灌注120 min下降最为明显[(189±7) ng/L vs (280±13) ng/L](P<0.01);血浆MDA在各再灌注时点表达水平也均下降(P<0.05),以再灌注60 min下降最为明显[(3.69±0.17) μmol/L vs (5.01±0.14) μmol/L](P<0.01)。Spr+o组再灌注各时点肺组织病理损伤与I/R组比较均有所减轻。 结论 七氟烷预处理联合后处理减轻肺I/RI,其机制可能与下调ACE mRNA表达有关。

关键词: 七氟烷; 预处理; 后处理; 肺损伤; 血管紧张素转化酶; mRNA
Abstract:

Objective To investigate the effects of sevoflurane preconditioning combined with postconditioning on the expression of pulmonary angiotensin converting enzyme (ACE) mRNA in lung tissues during lung ischemia/reperfusion injury(I/RI) in rats. Methods Fifty-four SD rats were randomly divided into three groups, 18 in each: sham operation group (S group), the left pulmonary hilum was only isolated but not ligated. Lung ischemia/reperfusion(I/R) group (I/R group), rats was induced by clamping the left pulmonary hilum for 45 min followed by 120 min reperfusion for preparing rat lung I/R model. Sevoflurane preconditioning combined with postconditioning group (Spr+o group), 2.1% sevoflurane was inhaled for 30 min, elution 10 min, the left pulmonary hilum was clamped for 45 min,and then perfusion was restored and the same time 2.1% sevoflurane was inhaled for 30 min. Six rats in each group were chosen at 30, 60 min and 120 min of reperfusion and sacrificed, lungs were removed for determination of wet-to-dry weight ratio (W/D), histological examination[by hematoxylin-eosin staining(HE)], the expression of malondialdehyde(MDA, by colorimetry method), endothelin-1(ET-1) concentration in plasma [by enzyme-linked immunosorbent assay (ELISA)], the expression of ACE mRNA[by reverse transcription-polymerase chain reaction(RT-PCR)]. Results Compared with S group, the W/D, the expression of ACEmRNA, ET-1 and MDA in rats were increased in groups Spr+o and I/R (P<0.05). Compared with the I/R group, Spr+o group in reperfusion 30, 60, 120 min, the W/D were decreased significantly [(4.74±0.14) vs (5.01±0.05), (4.96±0.07) vs (5.18±0.10), (5.31±0.11) vs (5.53±0.20)](P<0.05), ACE mRNA expression levels in reperfusion 30, 60, 120 min were also significantly decreased [(0.49±0.08) vs (0.70±0.09), (0.66±0.05) vs (0.82±0.07), (0.77±0.04) vs (0.92±0.04)](P<0.05), the ET-1 expression levels were decreased(P<0.05) and in reperfusion 120 min was decreased significantly [(189±7) ng/L vs (280±13) ng/L](P<0.01), the MDA expression levels were decreased(P<0.05) and in reperfusion 120min was decreased significantly [(3.69±0.17) μmol/L vs (5.01±0.14) μmol/L](P<0.01). Microscopic examination showed that the pathologic changes were significantly improved in Spr+o group compared with I/R group. Conclusions Sevoflurane preconditioning combined with postconditioning can reduce lung I/RI, which may be associated with downing-regulation of ACE mRNA.

Key words: Sevoflurane; Preconditioning; Postconditioning; Lung injury; Angiotensin converting enzyme; mRNA