高血压大鼠大脑中动脉内膜超微结构观察

目的:观察高血压大鼠大脑中动脉内膜的超微结构变化。方法:双肾双夹法建立肾血管性高血压大鼠模型,分别于7d、30d、90d处死动物,取大脑中动脉始段,用透射电镜观察。结果:高血压组7d内皮细胞肿胀明显,细胞膜呈虫蚀样改变,胞质内空泡明显增多,线粒体肿胀,呈大小不等的圆球状,内弹力膜肿胀,可见较多的空泡,局部增厚,与内皮细胞之间的边界模糊不清,核周隙增宽;30d内皮细胞和内弹力膜的变化与7d相似,肿胀略有减轻,但内皮细胞伸出伪足伸入内弹力膜形成的肌内皮细胞样连接多见;90d内皮细胞肿胀较7d、30d减轻,但线粒体肿胀更加明显,而且数量增多,可见散在的糖元颗粒,另外,内皮细胞间连接破坏明显,失去正常的形态,内弹力膜肿胀减轻,但仍可见空泡样改变,而且局部变薄,内皮下间隙增宽。结论:高血压大鼠脑动脉内膜结构的改变存在从水肿、肿胀减轻到结构性破坏的变化过程,这种变化可能是其在高血压晚期发生脑卒中的病理学基础。

Intima ultrastructural changes of middle cerebral artery in hypertensive rats

Objective; To observe the intima ultrastructure of middle cerebral artery in hypertensive rats. Methods: After establishing two kidneys-two clamps renovascular hypertensive rat models, rats were killed and the intima ultrastructure of the middle cerebral artery were observed by the transmission electron microscope on 7 d, 30 d, 90 d respectively. Results; On 7 d, endothelium cells of middle cerebral artery swelled evidently, the cell membrane offered worm-eclipsed shape, and the number of vacuoles in cell plasma increased. The swollen mitochondria were various in shape. Internal elastic lamina (IEL) with vacuoles swell and incrassated partly, the boundary between endothelium cell and IEL was indistinct, and the nuclear circumference gap became wider. On 30 d, the changes of endothelium and IEL were similar to on 7 d, endothe-lial cells protruded psendepodiums to IEL. On 90 d, the swollen lightened than 7 d and 30 d, but the mitochondrion swollen were more severe than 7 d and 30 d, and the number of mitochondrion and sugar granule increased, the junction of endothelial cells were injured, and the normal conformation loosed. Although the swollen IEL was palliative, the vac-uolating changes appeared and local IEL became thiner. Conclusion; Hypertensive rats intima of cerebral arteries have a process from swelling to structure destroy, which might be the basis of the occurrence of stroke in later hypertension.