Expression changes and its clinical significance of MMP-9 and TIMP-1 in neonatal rats with hypoxic-ischemic brain damage

MEI Mei; LI Hui-ling; LI Chun-yu; NIE Lei

doi:10.3969/j.issn.1002-266X.2015.24.008

Abstract：Objective To observe the expression changes of matrix metalloproteinase 9 ( MMP-9) and tissue inhibitor metalloproteinase (TIMP-1) in the brain tissue of rats with hypoxic-ischemic brain damage (HIBD) and to explore its sig-nificance .Methods Seventy-two neonatal rats were randomly divided into the observation group and control group , and 36 rats in each group .HIBD model was established in the observation group .In the control group , we separated the left com-mon carotid artery of rats and did not ligature , and rats were not treated with hypoxia .After 6 h ( T0 ) , 12 h ( T1 ) , 24 h (T2) and 72 h (T3), 5 d (T4), 7 d (T5) of modeling, 6 rats of each group were killed respectively.The pathological changes in the brain tissues was observed by HE staining after modeling for 72 h, the expression of MMP-9 and TIMP-1 in the brain tissues was detected by immunohistochemical SP method , and the water content of the brain tissues was calculat-ed.Results In the observation group , cortical brain edema , degeneration and necrosis of the cells were observed , the neuronal cells were decreased and inflammatory cells were increased;while, in the control group, the morphology structure of brain tissue was clear and complete , no interstitial hemorrhage , necrosis and edema were observed .The expression of TIMP-1 and MMP-9 in the brain tissues and the water content increased first and then decreased in the observation group , and no significant change was found in the control group .At T0-T5 in the brain tissues, the expression of MMP-9, TIMP-1 and water content in the observation group were higher than those of the control group (all P<0.05).Conclusion The expression of MMP-9 and TIMP-1 increases in the brain tissues of HIBD neonatal rats , and it may be related with the for-mation of HIBD in vasogenic brain edema .