Objective To investigate the effects of PJ34,a poly ADP-ribose polymerase(PARP)inhibitor,on the expression of matrix metallopro-teinases-9( MMP-9 )and Claudin-5 in ischemic cortex of rats with focal cerebral ischemia-reperfusion(I/R)injury. Methods The focal cerebral ischemia-reperfusion model of middle cerebral artery occlusion(MCAO)was established by intraluminal suture . PJ34 was injected intraperitoneal-ly. Blood-brain barrier(BBB)permeability was quantitatively determined by Evans blue assay. Infarct volume changes were observed by 2,3,5-tri-phenyltetrazolium chloridedyeing(TTC)staining. The expression of the MMP-9 and Claudin-5 in rats of cerebral cortex were measured by immuno-histochemistry assay and western blot analysis . Results Compared with sham group,the expression of MMP-9,the contents of EB and infarct vol-ume increased progressively over time after I/R,and reached maximum levels at 48 h(P<0.05);The expression of Claudin-5,the contents of EB and infarct volume reduced significantly over time after I/R,and reached the minimum levels at 48 h in model group(P<0.05). Compared with model group,the expression of MMP-9,the contents of EB and infarct volume was reduced significantly and the expression of Claudin-5,the con-tents of EB and infarct volume was increased at the same time point in PJ34 group(P<0.05). Conclusion PJ34 maintained the blood-brain barri-er permeability by inhibiting the expression of MMP-9,and increasing the expression of Claudin-5,which had neuroprotection on cerebral ischemia-reperfusion injury.

Objective To investigate the influence of poly(ADP-ribose)polymerase inhibitor PJ34 on blood brain barrier(BBB)in rats with cere-bral ischemia-reperfusion injury. Methods Rat model of cerebral ischemia-reperfusion injury was established by the middle cerebral artery occlu-sion. A total of 135 SD rats were randomly divided into 3 groups:sham-operated group(sham group),ischemia-reperfusion group(IR group)and PJ34 group(PJ34 group). 45 animals in each group were then equally divided into subgroups and the rats were sacrificed at 6 h,24 h,48 h after re-perfusion,respectively. BBB permeability was evaluated by detection of extravasated Evans blue(EB). The expression of tumor necrosis factorα(TNF-α)and matrix metalloproteinase 9(MMP-9)activity were measured by immunohistochemistry and western blot at different time points. Re?sults Compared with sham group,the contents of EB and the expressions of TNF-αand MMP-9 in IR group were increased significantly(P<0.05). Compared with IR group,the contents of EB and the expressions of TNF-αand MMP-9 in PJ34 group were markedly decreased at the same time point(P<0.05). Conclusion The present study provided in vivo evidence that PARP inhibitor PJ34 can protect against cerebral ischemia re-perfusion injury,and the mechanism might be related to maintaining the stability of blood-brain barrier by suppressing the expression of TNF-αand MMP-9 in ischemic cortex.