论文部分内容阅读
目的为进一步阐明模拟失重下脑血管结构重塑变化的细节与性质。方法利用透射电镜技术观察了４周尾部悬吊大鼠基底动脉管壁超微结构的变化，并与对照组进行比较。结果在４周尾部悬吊大鼠基底动脉管壁可见以下几种形式的变化：①平滑肌细胞由收缩表型转化为合成表型。表现为：平滑肌细胞由梭形变为多角形或不规则形。细胞突起周围可见有较多的由其分泌的胶原蛋白或弹性蛋白。胞质内除肌丝外，可见有较多的粗面内质网、高尔基体和线粒体。细胞间质增厚、增多。②迁移。此现象在近内弹力层的平滑肌细胞多见。可见中膜平滑肌细胞伸出较长的突起，穿越过附近的平滑肌细胞及内弹力层而到达内皮下层，此处的内弹力层结构变得模糊；还可见内皮下层局部增厚、有大量松散的细胞间质，其内可见有体积较小、圆形的合成表型平滑肌细胞；可见原内弹力层变薄，而在内皮下形成新的内弹力层，那些迁移来的平滑肌细胞渐变为梭形，处于部分合成表型。③增生。中膜平滑肌细胞层数增加，由对照组的４～５层增加到５～６层。细胞排列较对照组不够整齐。结论４周尾部悬吊可导致大鼠基底动脉血管管壁发生增生改变，血管平滑肌细胞重新排列，部分细胞也由收缩表型向合成表型转变，并出现细胞迁移现象。
The purpose is to further elucidate the details and nature of cerebral vascular remodeling under simulated weightlessness. Methods Transmission electron microscopy was used to observe the change of ultrastructure of the basilar artery wall in the tail suspension rats at 4 weeks and compared with the control group. Results The changes of the basilar artery wall in the tail suspension rats at 4 weeks showed the following changes: ① The smooth muscle cells transformed from the contractile phenotype to the synthetic phenotype. The performance is: smooth muscle cells from spindle to polygon or irregular shape. Around the protuberances are seen more collagen or elastin secreted by it. In addition to myofilament cytoplasm, we can see more rough endoplasmic reticulum, Golgi and mitochondria. Interstitial thickening, increased. ② migration. This phenomenon is more common in smooth muscle cells near the elastic layer. Visible smooth muscle cells in the medial membrane extended longer protuberances, through the nearby smooth muscle cells and the inner elastic layer and reach the endothelium, where the structure of the inner elastic layer becomes blurred; also see the local subendothelial thickening, a large number of loose Interstitial cells, which can be seen within the smaller, round synthetic phenotype smooth muscle cells; shows that the original inner elastic layer thinning, and under the formation of a new inner endometrial elastic layer, those migrating smooth muscle cells into a fusiform , In part synthetic phenotype. ③ hyperplasia. The number of SMMCs increased from 4 to 5 to 5 to 6 in the control group. Cell arrangement than the control group not tidy. Conclusions The tail suspension at 4 weeks can result in hyperplasia of vascular wall of basilar artery in rats, rearrangement of vascular smooth muscle cells, and the change of some cells from the contractile phenotype to the synthetic phenotype and the cell migration.