肢体缺血预处理减少肝门阻断再灌注后肠黏膜损伤和中性粒细胞浸润的实验研究

目的 观察肢体缺血预处理（LIP）对肝门阻断（HPO）再灌注损伤后肠黏膜损伤和中性粒细胞（PMN）浸润的影响,并探讨INF-α和细胞间黏附分子（ICAM-1）的作用.方法 将24只大鼠随机分为3组各8只,分别为假手术（Sham）组、HPO再灌注组（HPO组）和肢体缺血预处理＋HPO再灌注组（LIP＋HPO）组.以肠黏膜为目标,采用光镜病理学Chiu评分系统评价肠损伤程度,测定髓过氧化物酶（MPO）、评价PMN浸润程度,以放免法和ELISA法分别测定肠黏膜组织INF-α和ICAM-1含量.结果 HPO组肠黏膜损伤明显,PMN浸润程度较高,MPO活性明显升高（P〈0.01）,同时组织中TNF-α和ICAM-1浓度升高明显（均P〈0.05）;LIP＋HPO组肠损伤减轻,MPO活性降低,但TNF-α、ICAM-1水平仍高于Sham组（均P〈0.05）.结论 HPO后肠黏膜损伤严重,致炎因子TNF-α大量生成,激活了PMN并使其聚集;ICAM-1介导了PMN细胞毒效应,可致肠黏膜屏障损伤.LIP通过抑制肠黏膜组织中TNF-α和ICAM-1的生成,可减少PMN浸润,减轻肠黏膜屏障损伤.

Experimental study of limb ischemic preconditioning to alleviate intestinal mucosa injury and neutrophil infiltrations after hepatic portal occlusion reperfusion

Objective To observe the effect of limb ischemic preconditioning （LIP） on the intestinal mucosa injury and neutrophil infiltration after hepatic portal occlusion （HPO） reperfusion in vivo and explore the role of TNF-α and ICAM-1. Methods In the research, the Pringle＇ measure was used to install HPO model without bypass and hind limb tourniquet method was used to install LIP model by occlusion five rain/reperfusion five min and four times in rats. The morphology were studied by light microscope and with the Chiu scores the intestine injury was evaluated. The 24 rats were randomly divided into three groups （n=8） . control （sham） group, the HPO reperfusion group （HPO group）, limb ischemic preconditioning＋ HPO group （LIP ＋ HPO group）, respectively. Polymorphonuclear （PMN） infiltration level in intestine mucosa was evaluated by the determination of myeloperoxidase （MPO）. The contents of TNF-α and ICAM-1 in intestine mucosa were determined by radioimmunoassay or ELISA. Results Compared with sham group, the intestine mucosa injury and PMN infiltration in HPO group were more serious, meanwhile the contents of TNF-a and ICAM-1 in intestinal mucosa were all increased obviously （P〈0.05, respectively）, the intestine injury and PMN infiltration in LIP＋ HPO group were all mitigated and the contents of TNF-α and ICAM-1 were decreased （P〈0.05, respectively）, but higher than that in sham group （P〈0.01, respectively）. Conclusion HPO induces serious intestine mucosa injury. Limb ischemia preconditioning can decrease PMN infiltration and TNF-α and ICAM-1 to mitigate intestinal injury.