右美托咪定预处理缓解肠缺血再灌注诱发老年大鼠肺损伤的作用

Pretreatment of Dexmedetomidine on the Remission of Lung Injury Induced by Intestinal Ischemia-reperfusion in Elderly Rats

目的评估右美托咪定缓解肠缺血再灌注引起老年大鼠肺部损伤的作用。方法选择18月龄以上的健康老年雄性SD大鼠30只(体重220~240 g),随机分为3组,每组10只。假手术组(S组)不对肠系膜上动脉(SMA)进行夹闭,缺血再灌注组(I/R组)夹闭SMA 1 h后再灌注2 h,右美托咪定组(D组)右美托咪定提前10 min干预后再行再灌注。采集血样和肺组织,检测二者中超氧化物歧化酶(SOD)、丙二醛(MDA)、髓过氧化酶(MPO)、IL-1β和TNF-α的水平;HE染色观察肺组织病理学改变。结果与S组比较,I/R组和D组肺组织湿干重(W/D)比值显著升高(P<0.05),肺组织和血浆中SOD活性显著降低(P<0.05),MDA含量、MPO、IL-1β和TNF-α的水平则均显著升高(P<0.05)。与I/R组比较,D组SOD活性升高(P<0.05),其它各项指标包括W/D比值和肺通透性指数均明显降低(P<0.05),D组MDA含量、MPO、IL-1β和TNF-α的水平也呈显著下降(P<0.05);D组肺部病理学损伤较I/R组减轻。结论右美托咪定可有效缓解老年大鼠肠缺血再灌注引起的肺损伤,推测其可能参与抑制炎症和脂质过氧化反应。

Objective To investigate the impact of dexmedetomidine on lung injury induced by intestinal ischemiareperfusion(I/R)in elderly rats.Methods 30 healthy elderly male Sprague-Dawley rats(220-240 g),aged over18 months,were randomly divided into 3 groups:sham-surgery group(group S),intestinal I/R group(group I/R)and dexmedetomidine group(group D),10 in each;Intestinal I/R was prepared via the superior mesenteric artery(SMA)occlusion for 1 h was made to the anesthetized rats in group I/R before reperfusion for 2 h while dexmedetomidine at the dose of 30 g/kg was injected intraperitoneally to the rats in group D 10 min before reperfusion;no SMA was made to rats in group S;samples of lung tissues and serumwere collected and the levels of superoxide dismutase(SOD),malondialdehyde(MDA),myeloperoxidase(MPO)and the concentration of IL-1β and TNF-α were detected;HE staining was applied in observing the pathological change of lung tissues.Results Compared with group S,the lung wet/dry weight ratios(W/D),the levels of MDA,MPO,IL-1β and TNF-α were much more up-regulated while the SOD levels in lung tissues and serum dropped down more significantly in rats of group I/R and group D than those in group S(P<0.05);the increase of SOD level and the decrease of other parameters includingW/Dand lung permeability index in groupDwere greater than those in group I/R(P<0.05)and the levels of MDA,MPO,IL-1β and TNF-α in group D dropped down much more than those in group I/R(P<0.05);the pathological injury of lung in rats of group D was slighter than that in group I/R.Conclusions Dexmedetomidine can alleviate the lung injury induced by intestinal I/R,which may involve in inflammatory response inhibition and lipid peroxidation.