丁基苯酞对局灶性脑缺血过程中线粒体损伤的保护作用

目的　探讨抗脑缺血新药丁基苯酞(NBP)对缺血脑线粒体结构和功能的影响，以阐明其改善缺血脑损伤的作用机制。方法　用大鼠大脑中动脉阻断(MCAO)和原代培养神经元的低糖低氧损伤模型，测定神经细胞线粒体的膜流动性、膜电位、总ATPase活性和超微结构的影响。结果　大鼠于MCAO后1 h线粒体膜流动性显著降低。经低糖低氧处理后神经细胞线粒体膜电位和总ATPase活性也明显降低。NBP ip能逆转缺血期线粒体膜流动性降低; dl-,l-和d-NBP能使线粒体膜电位和线粒体总ATPase活性恢复至正常水平。电镜结果显示NBP能明显改善脑缺血再灌引起的线粒体肿胀和空泡化。结论　NBP从形态和功能方面对线粒体发挥保护作用，从而改善缺血脑的损伤。

THE PROTECTIVE EFFECT OF BUTYLPHTHALIDE AGAINST MITOCHONDRIAL INJURY DURING CEREBRAL ISCHEMIA

AIM　To study the effects of butylphthalide(NBP) on the function and ultrastructure of neuronal mitochondria during cerebral ischemia. METHODS　Cerebral ischemia models of rat middle cerebral artery occlusion in vivo and primarily cultured neurons subjected to hypoxia/hypoglycemia in vitro were used. The mitochondria was prepared for measurement of mitochondria membrane fluidity(MMF), mitochondria membrane potential(MMP) and the total activity of mitochondria ATPase. MMF was assessed with fluorescent probes diphenylhexatriene(DPH) and MMP was measured with the fluorescence of loaded rhodamine-123 using flow cytometry. Electron microscopy was also used to study the morphological changes of neuronal mitochondria. RESULTS　The value of η was enhanced significantly in the vehicle(MCAO) group. It means that the MMF was decreased deeply during the early stage of cerebral ischemia. The decrease of MMP and total ATPase activity were found in rat fetal neurons subjected to 3 h-hypoxia/hypoglycemia. The results indicate that after pretreatment with dl-NBP(5 mg.kg^-1 and 10 mg.kg^-1 ip), the MMF was close to that of the control level. The decrease of MMP and ATPase activity were not found following treatment with dl-, l-, and d-NBP(10 μmol.L^-1). In addition, NBP was found to improve the severe swelling and marked vacuolation of mitochondria in morphology. CONCLUSION　The results suggest that the improving effects of NBP on mitochondrial injury and morphological changes might contribute to its therapeutic action on experimental stroke.