右美托咪定对大鼠肺缺血再灌注时脂质过氧化反应的影响

Effect of dexmedetomidine on lipid peroxidation during lung ischemia-reperfusion in rats

目的评价右美托咪定对大鼠肺缺血再灌注时脂质过氧化反应的影响。方法清洁级健康雄性Wistar大鼠54只，体重250～350g，采用随机数字表法分为3组（n=18）：假手术组（S组）、缺血再灌注组（I／R组）和右美托咪定组（Dex组）。Dex组尾静脉注射右美托咪定5μg／kg，1次／d，连续2d；S组和I／R组静脉注射等容量生理盐水。I／R组和Dex组第2天给药后30min时，采用夹闭左肺门45min恢复灌注的方法建立大鼠肺缺血再灌注损伤模型。分别于缺血45min、再灌注60和120min时随机取6只大鼠处死取左肺，观察病理学结果，称湿重和干重，计算肺湿重／干重（w／D）比值，检测肺组织MDA含量和SOD活性。结果与s组比较，I／R组和Dex组再灌注60和120min时肺组织SOD活性降低，MDA含量和肺W／D比值升高（P〈0．05）；与I／R组比较，Dex组再灌注60和120min时SOD活性升高，MDA含量和肺W／D比值降低（P〈0．05）。Dex组肺组织病理学损伤较I／R组减轻。结论右美托咪定通过抑制脂质过氧化反应减轻大鼠肺缺血再灌注损伤。

Objective To evaluate the effect of dexmedetomidine on lipid peroxidation during lung isehemia-reperfusion （I/R） in rats. Methods Fifty-four pathogen-free healthy male Wistar rats, weighing 250-350 g, were randomly divided into 3 groups （n= 18 each） using a random number table： sham operation group （S group） , I/R group, and dexmedetomidine group （Dex group）. In group Dex, dexmedetomidine 5 p,g/kg was injected via the caudal vein once a day for 2 consecutive days. The equal volume of normal saline was given in S and I/R groups. At 30 rain after administration on 2nd day, lung I/R was produced by clamping the left hilum of lung for 45 rain followed by 120 rain of reperfusion in I/R and Dex groups. At 45 min of isehemia, and 60 and 120 min of reperfusion, 6 rats selected from each group were sacrificed, and the left lungs were removed for examination of the pathological changes and for determination of wet/dry lung weight ratio （W/D ratio）, malondialdehyde （MDA） content and superoxide dismutase （SOD） activity. Results Compared with S group, the SOD activity was significantly decreased, and the MDA content and W/D ratio were significantly increased at 60 and 120 min of reperfusiou in I/R and Dex groups （P〈0.05）. Compared with I/R group, the SOD activity was significantly increased, and the MDA content and W/D ratio were significantly decreased at 60 and 120 rain of repeffusion in Dex group （P〈0.05）. The pathological changes of lungs were significantly attenuated in Dex group as compared with I/R group. Conclusion Dexmedetomidine mitigates lung I/R injury through inhibiting lipid peroxidation in rats.