芳香开窍药对脑缺血再灌注损伤大鼠血脑屏障影响的实验研究

Effects of aromatic resuscitation drugs on blood brain barrier in cerebral ischemia-reperfusion injury model rats

目的:研究麝香、冰片、安息香和苏合香4味芳香开窍药对脑缺血再灌注损伤大鼠血脑屏障结构与功能的影响。方法:线栓法制备局灶性脑缺血再灌注损伤大鼠模型,透射电镜观察缺血侧半球额顶区皮质血脑屏障的超微结构,ELISA法测定缺血侧脑组织中血管内皮细胞生长因子(VEGF)及基质金属蛋白酶-9(MMP-9)的含量。结果:电镜结果显示,模型和溶媒组大鼠缺血侧半球额顶区皮质区域毛细血管内皮细胞、星型胶质细胞及神经元均出现不同程度的损伤,内皮细胞间的紧密连接打开,基膜溶解,细胞水肿较为严重。冰片(200 mg.kg-1)组大鼠的3种细胞结构基本正常,紧密连接结构较清晰,多数细胞器无显著异常表现;麝香(66.6 mg.kg-1)组大鼠毛细血管内皮细胞和星型胶质细胞结构基本规则,但神经元内的电子分布不均匀;苏合香(1.332 g.kg-1)组大鼠星型胶质细胞结构基本正常,但毛细血管内皮细胞和神经元均呈现不同程度的水肿表现;安息香(1.0 g.kg-1)组大鼠毛细血管内皮细胞和星型胶质细胞水肿明显,部分神经元有轻微水肿现象。此外,冰片能显著降低缺血侧脑组织中VEGF含量,但对MMP-9影响不明显;麝香有降低VEGF与MMP-9含量的趋势;苏合香与安息香的作用不明显。结论:芳香开窍药对脑缺血再灌注损伤大鼠血脑屏障结构的损伤有一定保护作用,作用机制可能与下调VEGF,MMP-9水平有关,其中冰片作用为优,麝香次之,苏合香和安息香作用较弱。

Objective： To research the effects of moschus,borneol,styrax and benzoinum on the structure and function of blood brain barrier in cerebral ischemia-reperfusion injury model rats.Method： Focal middle cerebral artery occlusion（MCAO） was introduced as an in vivo ischemic model in rats.After 2 h MCAO,nylon suture was pulled up 1 cm to give blood reperfusion.After 22 h reperfusion,all animals were decapitated.The ultramicrostructure of blood brain barrier of ischemia hemisphere side in fronto-parietal cortex region by transmission electron microscope,and the content of VEGF and MMP-9 in ischemia side brain tissue were measured by ELISA.Result： In model and solvent group rats,the capillary endothelium cells,astro-glial cells and nerve cells in ischemia hemisphere side in fronto-parietal region were emerged in different degree compared with sham-operated groups,which exhibited tight junction between endothelial cells being opened,basal lamina being dissolved,and permeability increasing,and cellularedema.In borneol（0.2 g·kg-1）group rats,the structure of three kinds of cells were nearly normal,which tight junction structure was clear,rough endoplasmic reticulum and polyribosome could be found in cytoplasm.In moschus（66.6 mg·kg-1）group rats,the structure of capillary endothelium cells and astrocytes were nearly normal as well as the basal lamina,but the electrons in neurons was maldistribution.In styrax（1.332 g·kg-1）group rats,astrocytes were nearly normal,while capillary endothelial cells and neurons exhibited oedema in different degrees.And the basal lamina was discontinuous,augmentation of cell spaces in endothelial cells increased the permeability,some endoplasmic reticulum broadened and ribosome ablated.In benzoinum（1.0 g·kg-1）group rats,oedema of capillary endothelial cells and astrocytes was significant,basal lamina broke.Meanwhile endoplasmic reticulum broadened as vacuole,the number of ribosome in rough endoplasmic reticulum decreased,crista mitochondriales in some neurons disappeared as vacuole which hint oedema happened.Results also showed that borneol decrease the level of VEGF in ischemia side brain tissue significantly,while has little influence on the level of MMP-9.Moschus showed the tendency to decrease the level of VEGF and MMP-9 in ischemia side brain tissue.Conclusion： Aromatic resuscitation drugs showed the protection effect on blood brain barrier in cerebral ischemia-reperfusion injury rats,which the protection effect of moschus and borneol were better than that of styrax and benzoinum.The mechanism of protection effect maybe related to decrease the level of VEGF and MMP-9.