应激状态下大鼠肠屏障功能损伤过程中MMP-13、LN的改变及意义

SIGNIFICANCE OF CHANGES IN EXPRESSION OF LN AND MMP-13 IN INTESTINAL MUCOSA UNDER STRINGENT STATE

目的探讨应激状态下大鼠肠黏膜基质金属蛋白酶-13(MMP-13)和层粘连蛋白(LN)的改变及意义。方法Wistar大白鼠60只,随机分为3组,每组20只。实验组制备肠缺血再灌注模型,对照组只进行同样腹部手术操作但不夹闭肠系膜上动脉,正常组不手术。6h后处死大鼠,取距回盲部15cm处肠管1cm,常规组织切片,苏木精-伊红染色观察肠黏膜组织细胞学形态;用免疫组织化学方法染色显示肠黏膜组织或细胞中LN、MMP-13的表达情况,并用VIDAS图像分析系统进行半定量分析。结果苏木精-伊红染色显示:实验组与对照组相比,肠壁变薄,上皮细胞水肿明显,部分坏死脱落,中性粒细胞及淋巴细胞浸润。免疫组织化学染色显示:实验组肠黏膜组织中MMP-13表达较对照组增高,基底膜LN表达较对照组降低,差异有显著性(t=3.31、3.46,P<0.01),而对照组与正常组相比差异无显著性(P>0.05)。结论缺血再灌注可使肠黏膜组织中MMP-13水平表达增高,进而使其降解底物LN水平降低,肠黏膜萎缩及通透性增大,导致肠屏障功能损伤。

Objective To investigate changes of expressions of LN and MMP-13 in impaired intestinal mucosa during stringent state. Methods Sixty Wistar rats were evenly randomized into three groups： experimental, control, and normal con trol. For experimental group, a model of post ischemic-reperfusion intestine was established by clamping the superior mesenteric artery; for control group, a laparotomy was merely done without clamping any arteries; for those in normal control group, received nothing. A 1-cm-long segment of intestine, 15 cm above the ileocecal junction, was dissected 6 hours later, and a tissue section made as routine. Immunohistochemical study was used to observe the expressions of MMP-13 and LN and VIDAS image analysis system applied for semi-quantitative detection. Results The thinner enteric wall, edematous epithelium with neutrophils and lymphocytes infiltration, shorter intestinal villi were obviously noticed in the experimental group compared with the other two. Immunohistochemically, the expression of MMP-13 in the experimental was higher and the expression of LN was lower compared with those in the control （t =3.31,3.46;P〈0.01）. Conclusion Postischemic reperfusion may elevate the expression of MMP-13 in intestinal mucosa and leads to lower expression of LN, shrink the mucosa and increase its permeability, thus damage the intestinal mucosal barrier.