Effect of the matrix metalloproteinases-2, matrix metalloproteinases-9 and tissue inhibitor metalloproteinases-3 in the rats with cerebral infraction caused by injection of auto blood thrombus

Objective To investigate the effect of the cerebral infarction in rats and the role of matrix metalloproteinases-2 (MMP-2), matrix metalloproteinases-9 (MMP-9), and tissue inhibitor of metalloproteinases-3 (TIMP-3) in the pathogenesis. Method Sixty-six rats were randomly divided into 3 groups: blank group (n= 6), control group (n=30), model group (n=30). The rat model was established by carotid injection of auto blood thrombus, the control group was given the operation without injection. Each group was subdivided into 24 hours, 48 hours, 3 days, 5 days, 7 days after operative intervention. At serial intervals, the animals in each group were sacrificed and brain tissue samples were collected to determine MMP-2, MMP-9, TIMP-3 expression by immunohistoehemistry. The changes of behaviors were observed and the histopathological changes were investigated by hematoxylin and eosin stain. Results The experimental group had more obvious behavior change than other groups. Hematoxylin and eosin stain showed significant histopathological changes; MMP-2, MMP-9 and TIMP-3 expression was up-regulated in comparison with other groups (P0.05). Conclusions The higher expression of MMP-2 and MMP-9 were derived from the injury and brain dysfunction in cerebral infraction. TIMP-3 inhibited the effect of the MMP-2 and MMP-9 activation.