dl-3-n-butylphthalide attenuates reperfusion-induced bloodbrain barrier damage after focal cerebral ischemia in rats

AIM: To study the protective effect of dl-3-n-butylphthalide (NBP) on blood -brain barrier (BBB) damage induced by reperfusion following focal cerebral ischemia. METHODS: Focal cerebral ischemia in rats was performed by insert ing a nylon suture into intracranial segment of internal carotid artery to block the origin of middle cerebral artery and reperfusion by withdrawing t he nylon suture. Permeability of BBB was determined by extravasation of the protein-bound Evans blue dye to cerebral cortex and further evaluated by i mmunohistochemical or electronmicroscopic method. RESULTS: Reperfusion for 3 h following focal cerebral ischemia for 3 h produced BBB damage which exh ibited the increase in extravasation in cerebral cortex, elevation of the e xpression of immunoglobulin and pore formation in endothelial cell membrane of capillary in cerebral cortex. NBP (5 - 20 mg . kg(-1)) decreased the ex travasation in a dose-dependent manner. The expression of IgG in cerebral c ortex was decreased and the ultrastructure damage of capillaries was allevi ated after treatment with NBP. NBP 20 mg . kg(-1) also alleviated brain ede ma caused by 3-h reperfusion following 3-h middle cerebral artery occlusion (MCAO). CONCLUSION: NBP has protective effect on BBB damage induced by rep erfusion after MCAO.