远隔缺血后适应对大鼠小肠缺血再灌注损伤的保护作用

Protective Effect of Remote Ischemic Postconditioning on Intestinal Ischemia-Reperfusion Injury in Rats

目的探讨远隔缺血后适应是否对大鼠肠道缺血再灌注损伤起保护作用。方法健康雄性昆明种大鼠24只,随机分为假手术组(Con组)、缺血再灌注组(ischemia reperfusion,IR组)和远隔缺血后适应组(remote ischemic postconditioning,RIP组)共3组,每组8只。Con组只给予解剖游离肠系膜上动脉;IR组解剖出肠系膜上动脉,在肠系膜上动脉缺血60min后再灌注120min;RIP组在肠系膜上动脉缺血20min后捆绑左下肢形成4个间隔5min的循环缺血再灌注(共40min),再进行再灌注2h。测定回肠组织中丙二醛(maleiedialdehyde,MDA)和髓过氧化物酶(myeloperoxidase,MPO)的含量;光镜下观察肠道组织形态学改变,对小肠黏膜损伤程度进行评分。结果光镜下观察IR和RIP组有明显的肠道损伤,RIP组肠道损伤程度明显较IR组轻。小肠损伤按Chiu氏评分,RIP组Chiu评分值(2.10±0.63)明显低于IR组(3.20±0.76)(P<0.05)。IR和RIP组回肠组织中MDA和MPO含量明显高于Con组(均P<0.05),而RIP组回肠组织中MDA及MPO含量明显低于IR组(均P<0.05)。结论远隔缺血后适应对小肠缺血再灌注损伤具有显著保护作用,这种远隔器官缺血后适应可能是通过减轻活性氧损伤及炎症反应来保护肠道。

Objective To investigate the protective effect of remote ischemic postconditioning（RIP）on intestinal ischemiareperfusion injury in rats.Methods Twenty-four male Kunming rats were randomly divided into 3groups：sham operation group（Con）,ischemia-reperfusion group（IR）and remote ischemic postconditioning group（RIP）.Animals in Con group only received the dissection of superior mesenteric artery.Animals in IR group were subjected to 60-min superior mesenteric artery ischemia followed by 120-min reperfusion.RIP consisted of 4cycles of 5-min hind limb ischemia followed by 5-min hind limb perfusion,which was contemporaneous to the last 40-min superior mesenteric artery ischemia.After 2-h reperfusion,the ileum tissues were harvested for measurement of malondialdehyde（MDA）and myeloperoxidase（MPO）.The intestinal morphological changes were observed.Scoring for the degree of intestinal mucosal injury was done.Results Light microscopy revealed that there were severe intestinal injuries in both RIP and IR groups.However,RIP group relative to IR group had significantly attenuated injuries.The Chiu score was（2.10±0.63）in RIP group,significantly lower than in IR group（3.20±0.76）（P〈0.05）.The concentrations of MDA and MPO were significantly increased in ileum tissues in both IR and RIP groups when compared with Con group（P〈0.05）.Those were significantly lower in RIP group than in IR group（P〈0.05）.Conclusion RIP protects against intestinal ischemia reperfusion injury in rats probably by reducing reactive oxygen injury and inflammatory response.