论文部分内容阅读
目的研究大鼠视神经血视神经屏障与血脑屏障微血管内皮细胞在超微结构、标记物表达及通透性方面的差异。方法 SD 雄性大鼠20只,分别取筛板前区、筛板区、筛板后区、眶内段、管内段、颅内段和前额叶皮层。10只用电镜观察各部位微血管内皮细胞的超微结构;10只用免疫组织化学的方法检测内皮屏障抗原(EBA)的表达及微血管周围纤维蛋白原外渗情况。结果电镜显示视神经各段和前额叶皮层微血管内皮细胞均为紧密连接,以30 000倍拍摄微血管内皮细胞。将5 mm 透明方格网重叠于照片上,随机数3个方格质膜囊泡数,最终折算成每μm~2内膜内质膜囊泡的数量。筛板前区内皮细胞质膜囊泡为(108.0±12.0)个,多于前额叶皮层[质膜囊泡(31.8±2.9)个],差异有统计学意义(P<0.05);而筛板区内皮细胞质膜囊泡(30.4±2.8)个、筛板后区(30.3±3.0)个、眶内段(31.3±3.8)个、管内段(28.9+2.0)个和颅内段(30.1±2.1)个与前额叶皮层比较差异均无统计学意义(均 P>0.05)。免疫组织化学显示筛板前区微血管内皮细胞 EBA 表达阴性。微血管周围纤维蛋白原阳性;而筛板区、筛板后区、眶内段、管内段、颅内段和前额叶皮层 EBA 阳性表达。微血管周围纤维蛋白原阴性。结论视神经筛板前区微血管内皮细胞在超微结构、标记物表达及通透性方面与前额叶皮层存在差异,因而不具有血脑屏障特性,而筛板区、筛板后区、眶内段、管内段和颅内段与前额叶皮层存在相似的特性,故具有血脑屏障特性。
Objective To investigate the differences in the ultrastructure, marker expression and permeability between the optic nerve barrier and the blood-brain barrier microvascular endothelial cells in the optic nerve of rats. Methods Twenty male Sprague Dawley rats were divided into three groups: the anterior plaque area, the trabecular area, the posterior area of the trabecular meshwork, the orbital segment, the medial segment, the intracranial segment and the prefrontal cortex. The ultrastructure of microvascular endothelial cells was observed with electron microscopy in 10 of them. The expression of endothelial barrier antigen (EBA) and the extravasation of fibrinogen around the microvessels were detected by immunohistochemistry. Results Electron microscopy showed that the sections of the optic nerve and the prefrontal cortex microvascular endothelial cells were closely linked to capture microvascular endothelial cells at 30 000 times. A 5 mm clear grid overlaid on the photograph was randomized to three squares of the number of membrane vesicles and finally converted to the number of plasma membrane vesicles per μm ~ 2 intima. (108.0 ± 12.0), which was more than that of the prefrontal cortex (31.8 ± 2.9) in the pre-plate area, the difference was statistically significant (P <0.05) There were 30.4 ± 2.8 cytoplasmic vesicles, 30.3 ± 3.0 posterior lamina propria, 31.3 ± 3.8 posterior orbital segments, 28.9 ± 2.0 and 30.1 ± 2.1 intracranial segments, Compared with the prefrontal cortex, there was no significant difference (all P> 0.05). Immunohistochemistry showed that EBA expression in the pre-platelet microvascular endothelial cells was negative. Periplasmic fibrinogen positive; while the plate area, the area after the plate, the orbital segment, the tube segment, intracranial segment and prefrontal cortex EBA positive expression. Microvascular fibrinogen negative. CONCLUSION: The microvascular endothelial cells in the anterior segment of the optic nerve are different from the prefrontal cortex in ultrastructure, marker expression and permeability, and therefore do not have the characteristics of blood-brain barrier. However, the area of the trabecular meshwork, the posterior area of the sieve plate, the orbital segment, The intracranial and intracranial segments have similar characteristics to the prefrontal cortex and therefore have blood-brain barrier properties.