Atorvastatin downregulates MMP-2,MMP-9 in brain of rats with focal cerebral ischemia-reperfusion

Objective To study the neuroprotective mechanism of atorvastatin against the injury induced by cerebral ischemia-reperfusion. Methods Wistar rats were randomly divided into: normal group (N),ischemia-reperfusion group (IR),sham-operation group (NS),atorvastatin group (At),atorvastatin treatment group (AtT) and atorvastatin preconditioning group (AtP). The rat model of focal cerebral ischemia-reperfusion was established by inserting a piece of nylon thread into the left internal carotid artery. Ischemia of 30 min and reperfusion of 30 min were carried out alternately for 12 h or 24 h respectively. Their expressions of MMP-2 and MMP-9 in brain tissues were measured by immunohistochemical methods and their optic density value was measured by imaging analysis system. The positive cells for MMP-2 and MMP-9 expressions were counted under optic microscope. Results The expressions of MMP-2 and MMP-9 in AtP and AtT groups were lower than those in IR group (P0.05),significantly higher than those in NS,N,At groups (P0.01); Infarct volume was smaller than that of in IR group (P0.05),significantly higher than that in NS,N,At groups (P0.01). Conclusion Atorvastatin can downregulate MMP-2 and MMP-9 expressions and restrain infarct volume during focal cerebral ischemia-reperfusion. The treatment with atorvastatin can protect neural function by maintaining the structural integrality of blood brain barrier.