多器官功能障碍综合征大鼠血清及肝组织中基质金属蛋白酶-9的表达及意义

Expression of matrix metalloproteinase - 9 in the serum and liver of rats with multiple organ dysfunction syndrome

目的 检测基质金属蛋白酶-9（MMP-9）在多器官功能障碍综合征（MODS）大鼠外周血清及肝组织中表达的变化,探讨细胞外基质的破坏在MODS肝损伤中的作用.方法 将40只成年雄性SD大鼠随机分为正常对照组（8只）、MODS模型组（32只）,模型组又分为造模后6、12、24、48 h不同时相,每组8只.采用＂二次打击＂即眼球失血加腹腔注射脂多糖（LPS）制备MODS模型：大鼠左眼球取血2 mL/100 g,4 h后无菌腹腔注射LPS 5 mg/kg.造模完成后在不同时相点收集标本.对照组予以腹腔注射等量的生理盐水.肉眼、光镜观察肝组织形态结构变化,酶联免疫吸附试验（ELISA）法检测血清MMP-9水平,免疫组化法检测肝组织MMP-9蛋白的表达.结果 正常对照组肝组织结构无改变,MODS组肝组织损伤较重.造模后6～24 h MODS组血清MMP-9水平高于正常对照组（P〈0.05）,其峰值见于造模后12 h（P〈0.05）,24 h开始下降,48 h虽高于正常对照组,但差异无统计学意义.造模后6～48 h MODS组肝组织MMP-9的阳性表达较正常对照组有所增加（P〈0.01,P〈0.05）,其峰值见于造模后12 h（P〈0.01）.结论 细胞外基质的破坏是引起MODS肝损伤的一个重要因素,早期检测MMP-9水平的变化,可能对MODS组织器官功能损害的早期诊断和预后判断有重要价值.

Objective To determine the expression of matrix metalloproteinase - 9 （ MMP - 9） in the serum and liver of rats with the muhiple organ dysfunction syndrome （MODS） and to investigate the mechanism of extracellular matrix damage of liver failure in MODS. Methods Forty adult male Sprague- Dawley （SD） rats were randomly divided into two groups, namely tile normal control group and the MODS model group. The rats of model group were furthedy divided into four subgroups as different intervals（6, 12, 24 and 48 h）,and there were 8 rats in each groups. The animal models of MODS were established by two hits, the left eyeball of each model rat was removed to bleed （2 mL/100 g） and lipopolysaecharide（ LPS,5 mg/kg） was injected into intraperitoneal cavity of model rats four hours later. The same volume of saline was injected intraperitoneally into rats of control group instead of LPS. All rats were sacrificed at various intervals. The histological changes in liver tissue were observed by naked eye and light microscope. The expressions of serum MMP -9 were detected by enzyme linked immunosorbent assay （ELISA） , and the MMP -9 protein expressions of liver tissue were detected by using immunohistochemistry. Results （1）There were no histnpathological changes in liver of rats of control group, and the liver injury was serious in MODS rats. （2）Compared with the rats of control group, the expression of MMP-9 in serum of MODS rats increased during 6 -24 h ＇after LPS （P 〈0.05） , the peak reached at 12 hours later （P 〈 0. 05）, and then decreased 24 hours. There was no significant difference in expression of MMP -9 between two groups 48 hours later. （3）Compared with the rats of control group, the expressions of MMP- 9 in liver tissue of MODS rats didn＇t significantly increase 6 48 h after LPS （ P 〈 0. 01 or P 〈 0. 05）, the peak reached at 12 hours later （P 〈 0. 01 ）. Conclusion The injury of extracellular matrix may be an important factor to the liver injury in MODS. To detect the change of MMP -9 level are helpful for early diagnosis and the severity evaluation of organ damage in MODS.