A Study On The Relationship Between The Expression Of Matrix Metalloproteinase-9 In Rat Brain And The Pathogenesis Of Epilepsy

Aim:To study the relationship between the expression of matrix metalloproteinase-9 in rat brain and pathogenesis of epilepsy.Methods: Acute epilepsy model was made by bemegride. The permeability ofblood brain barrier (BBB) was evaluated by the dyeing contents of Evans Blue (EB) in hippocampus with fluorescence microscope. The expression of matrix metalloproteinase-9 in hippocampus was observed by immunochemistry in normal and epilepsy rat. Meanwile, the effects of dexamethasone before epilepsy on the permeability of BBB and the expression of MMP-9 in hippocampus was evaluated.Results: The dose of EB permeating BBB and the expression of MMP-9 inhippocampus were fewer in normal rat brain. The dose of EB in hippocampus had increased after epilepsy 24h. It had increased more obviously after epilepsy 72h than 24h(P<0.01). The expression of MMP-9 had increased in hippocampus after epilepsy 24h. It had increased obviously in dentate gyrus (DG) after epilepsy 72h than 24h(P<0.01), while there was no obvious change about the expression of MMP-9 in Corner Ammon (CA)(P>0.05). Dexamethasone suppressed the EB permeating BBB and the expression of MMP-9 in hippocampus.Conclusions: The expression of MMP-9 in rat brain participates inimmunopathogenesis of epilepsy by affecting the permeability of BBB and brain immunoreaction resulted from the change of permeability of BBB, leading to the change of neuronal response and synapse remodeling in hippocampus,regulating brain nervous cell excitability. Dexamethasone play a prominent suppressant role in the processes.