小肠缺血再灌注损伤时自由基清除剂及MDA变化的实验研究

Experimental Study on the Changes of Free Radical Scavengers and MDA in Ischemia-reperfution Injury of Animal's Small Intestine

目的通过建立兔小肠缺血再灌注模型，观察自由基在小肠缺血再灌注损伤时的变化。方法完全阻断和开放兔肠系膜上动脉，分别测定各时段血液中雨二醛（ＭＤＡ）含量及过氧化氢酶（ＣＡＴ）、超氧化物歧化酶（ＳＯＤ）、谷胱甘肽过氧化物酶（ＧＳＨ－ＰＸ）的活性，观察肠组织形态学上的变化。结果ＭＤＡ含量随缺血和再灌注时间的延长而逐渐增高，且与小肠的损伤程度呈正相关；ＣＡＴ、ＳＯＤ、ＧＳＨ－ＰＸ活性随缺血和再灌注时间的延长而逐渐降低。结论小肠缺血后再灌注产生大量的自由基和ＭＤＡ，后者是造成组织损伤的主要原因之一。

Objective To investigate the changes of free radical in ischemia-reperfution injury of small intestine. Methods The model of small intestine ischemia reperfution injury was made in Newzealand white rabbits. The level of malondialdehyde (MDA) and the activities of free radical scav- engers,including catalase (CAT),superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) in blood were determined before ischemia, 30min and 60min after complete occlusion of superior mesen tery artery as well as 30 min and 60 min after reperfution respectively. The changes of intestine were ob served in histomorphology. Results The level of MDA was gradually increased after ischemia and reperfution,while the activities of CAT,SOD,GSH-PX were gradually decreased. The positive relation ship was found between the degree of intestine injury and the level of MDA. Conclusion The free radi cals and MDA were produced by ischemia-reperfution. The increase of MDA was one of the main rea sons causing intestinal injury.