中文摘要：

目的探讨瑞芬太尼对大鼠肺缺血再灌注损伤及血管紧张素转换酶（ACE）mRNA表达的影响。方法清洁级健康成年雄性SD大鼠40只，体重300～350g，采用随机数字表法，将大鼠随机分为5组（n=8）：假手术组（S组），肺缺血再灌注组（I／R组）及不同剂量瑞芬太尼组（R1组～R3组）。采用阻断左肺门45min再灌注120min的方法制备大鼠肺缺血再灌注模型。R1组～R3组于阻断左肺门前15min静脉注射瑞芬太尼负荷剂量1μg／kg，继而分别以0．2、0．6和1．2μg·kg^-1·min的速率静脉输注至再灌注120min。S组和I／R组给予等容量生理盐水。再灌注120rain时放血处死，取肺组织，光镜下观察病理学结果并行肺损伤评分，测定肺组织湿干重比（W／D比），采用RT-PCR法测定肺组织ACEmRNA表达水平。结果与S组比较，I／R组、R，组和R：组肺损伤评分升高，W／D比和ACEmR—NA表达上调，R3组肺损伤评分升高（P〈0．05），W／D比和ACEmRNA表达差异无统计学意义（P〉0．05）；与1／R组比较，R1组和心组肺损伤评分、W／D比降低，ACEmRNA表达下调，R1组肺损伤评分、W／D比降低（P〈0．05），ACEmRNA表达差异无统计学意义（P〉O．05）；与R1组比较，R3组肺损伤评分、W／D比降低，ACEmRNA表达下调（P〈0．05），R2组肺损伤评分、W／D比降低（P〈0．05），ACEmR—NA表达差异无统计学意义（P〉0．05）；与心组比较，K1组肺损伤评分、W／D比降低，ACEmRNA表达下调（P〈0．05）。R1组～R3组肺组织病理学损伤较I／R组减轻。结论瑞芬太尼可减轻大鼠肺缺血再灌注损伤，且呈剂量依赖性，其机制可能与下调ACEmRNA的表达有关。

英文摘要：

Objective To investigate the effects of remifentanil on lung ischemia-reperfusion （I/R） injury and expression of angiotensin-converting enzyme （ACE） mRNA in rats. Methods Forty pathogen-free adult male Sprague-Dawley rats, weighing 300-350 g, were randomly divided into 5 groups （ n = 8 each） ： sham operation group （group S） , group I/R and different doses of remifentanil groups （groups R1-R3 ）. Lung I/R was produced by occlusion of the left hilum of lung for 45 rain followed by 120 min reperfusion. Remifentanil was infused intraveno- usly at a rate of 0.2, 0.6 and 1.2 μg·kg^-1·min^-1 until 120 min of reperfusion after a loading dose of 1 μg/kg at 15 min before occlusion of the left hilum of lung in groups RI , R2 and R3 , respectively. The equal volume of nor- mal saline was given in groups S and I/R. The rats were scarified at 120 rain of reperfusion and lungs were removed for microscopic examination and determination of wet/dry lung weight ratio （W/D ratio） and the expression of ACE mRNA （by RT-PCR） in the lung tissue. The pathological changes of the lung were scored. Results Compared with group S, the pathological score and W/D ratio were significantly increased and the expression of ACE mRNAwas up-regulated in groups I/R, R1 and R2 , and the pathological score was significantly increased （P 〈 0.05）, and no significant change was found in W/D ratio and the expression of ACE mRNA in group R3 （ P 〉 0.05）. Compared with group I/R, the pathological score and W/D ratio were significantly decreased and the expression of ACE mRNA was down-regulated in groups R2 and R3, and the pathological score and W/D ratio were significantly decreased （P 〈 0.05） and no significant change was found in the expression of ACE mRNA in group R1（ P 〉 0.05）. Compared with group R1 , the pathological score and W/D ratio were significantly decreased and the ex- pression of ACE mRNA was down-regulated in group R3 , and the pathological score and W/D ratio were signifi- candy decreased