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.