中文摘要：

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／reperfusioninjury，I／RI）时肺组织血管紧张素转化酶（angiotensin convening 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45min后再灌注120min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30min，洗脱10min，阻断左肺门45min后，在恢复灌注同时吸入2．1％七氟烷30min。于再灌注30、60min和120min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），苏木精咿红（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、ACE mRNA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、120min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、120min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120min下降最为明显[（189±7）ng／Lvs（280±13）ng／L]（P〈0．01）；血浆MDA在各再灌注

英文摘要：

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 decr