乳化异氟醚预处理对大鼠肺缺血再灌注损伤的影响

Effects of emulsified isoflurane preconditioning on lung ischemia-reperfusion injury in rats

目的 探讨乳化异氟醚预处理对大鼠肺缺血再灌注损伤的影响.方法 雄性SD大鼠32只,体重250～ 320 g,采用随机数字表法分成4组（n=8）：假手术组（S组）、肺缺血再灌注损伤组（Ⅰ/R组）、脂肪乳组（IL组）和乳化异氟醚预处理组（El组）.采用阻断左肺门lh再灌注2h的方法制备肺缺血再灌注损伤模型.IL组腹腔注射30％脂肪乳10.5 ml/kg,EI组腹腔注射8％乳化异氟醚,24 h后制备模型.于再灌注2h时,取血样,测定PaO2和PaCO2,采用硫代巴比妥酸法测定血浆MDA浓度.处死大鼠,取左肺组织,光镜下观察肺组织病理学结果,计算湿重/干重（W/D）比值,采用比色法测定髓过氧化物酶（MPO）活性.结果 与S组比较,其余3组肺组织W/D比值、MPO活性、血浆MDA浓度和PaCO2升高,PaO2降低（P＜0.05）;与Ⅰ/R组比较,IL组和EI组肺组织W/D比值、MPO活性、血浆MDA浓度和PaCO2降低,PaO2升高（P＜0.05）;与IL组比较,EI组肺组织W/D比值、MPO活性、血浆MDA浓度和PaCO2降低,PaO2升高（P＜0.05）.EI组肺病理学损伤较Ⅰ/R组明显减轻.结论 乳化异氟醚预处理可减轻大鼠肺缺血再灌注损伤,其机制与抑制肺组织炎性反应和氧自由基生成有关.

Objective To investigate the effects of emulsified isoflurane preconditioning on lung ischemia-reperfusion （Ⅰ/R） injury in rats.Methods Thirty-two male Sprague-Dawley rats,weighing 250-320 g,were randomly divided into 4 groups （n =8 each） using a random number table：sham operation group （group S）,group Ⅰ/R,intralipid group （group IL）,and emulsified isoflurane preconditioning group （group EI）.Lung Ⅰ/R was produced by clamping the left hilum of lungs for 1 h followed by 2 h of reperfusion in anesthetized rats.In group S,intraperitoneal normal saline 10.5 ml/kg was injected,but the hilum was only exposed 24 h later.In groups Ⅰ/R,IL and EI,intraperitoneal normal saline 10.5 ml/kg,30% intralipid 10.5 ml/kg and 8% emulsified isoflurane 10.5 ml/kg were injected intraperitoneally,respectively,and then the model was established 24 h later.At the end of reperfusion,blood samples were collected from the left ventricle for measurement of PaO2,PaCO2,plasma malondialdehyde （MDA） concentration （by ELISA）.The rats were then sacrificed,and left lungs were removed immediately for microscopic examination and for determination of myleoperoxidase （MPO） activity （using colorimetric method） in pulmonary specimens.Wet/dry lung weight ratio （W/D ratio） was calculated.Results Compared with group S,W/D ratio,MPO activity,plasma MDA concentration and PaCO2 were significantly increased,and PaO2 was decreased in the other three groups.Compared with group Ⅰ/R,W/D ratio,MPO activity,plasma MDA concentration and PaCO2 were significantly decreased,and PaO2 was increased in IL and EI groups.W/D ratio,MPO activity,plasma MDA concentration and PaCO2 were significantly lower,and PaO2 was higher in group EI than in group IL.The pathological changes of the lung were significantly attenuated in group EI compared with group Ⅰ/R.Conclusion Emulsified isoflurane preconditioning can reduce lung Ⅰ/R injury in rats,and inhibition of pulmonary inflammatory responses and of production of oxygen free radicals are involved in the mechanism.