Relationship between matrix metalloproteinase-9 and tissue metalloproteinase inhibitor-1 and carotid atheromatous plaque stability

AIM: To investigate the correlation between matrix metalloproteinase-9 (MMP-9),tissue metalloproteinase inhibitor-1 (TIMP-1),MMP-9/TIMP-1 and carotid atheromatous plaque stability in cerebral infarction patients.METHODS: 80 patients with cerebral infarction were categorized as microemboli-negative group (n=70) and microemboli-positive group (n=10),20 normal human were served as control group.The MMP-9 and TIMP-1 levels in plasma were determined by mean of ELISA in 3 groups.RESULTS: The levels of MMP-9 and TIMP-1 in plasma were significantly higher in cerebral infarction patients than those in control group (P<0.01).The plasma MMP-9 content was positively correlated with TIMP-1 content (r=0.76，P<0.01).The ratio of MMP-9/TIMP-1 increased only in microemboli-positive patients (P<0.01).CONCLUSION: The results indicate that the plasma MMP-9 participates in pathophysiological process of cerebral infarction.The ratio of MMP-9/TIMP-1 shows a close relationship with carotid atheromatous plaque instability.