Geriatrics Research Institute , Maebashi, Gunma 371-0847, Japan.
Second Department of Pathology, Fukuoka University School of Medicine , Fukuoka 814-0180, Japan.
Acta Histochem Cytochem. 2014;47(5):211-7. doi: 10.1267/ahc.14006. Epub 2014 Sep 12.
Hypertensive rat arteries exhibited severe medial smooth muscle cell injury and necrosis. Electron microscopic observations showed the smooth muscle cells of these arteries exhibited characteristics of focal cytoplasmic necrosis forming new cytodemarcating membrane between the healthy cytoplasm and necrotic cytoplasm. When the focal necrotic cytoplasm disappeared from the injured smooth muscle cells, it left it with a moth-eaten leaf-like appearance (moth-eaten necrosis). At an advanced stage of injury, smooth muscle cells changed to islet-like cell bodies with newly formed basement membranes around them, and further islet-like cell bodies and cell debris disappeared leaving lamellar and reticular basement membranes. In hypertensive rats injected with nitroblue tetrazolium (NBT), formazan deposits were observed in the medial cells and nitrotyrosine, a biomarker of peroxynitrite, were immunohistochemically observed in the arterial media. Nick-end positive extranuclear small granular bodies, which might have derived from focal necrotic cytoplasm and nucleus, were detected in the arterial media using DNA nick-end labeling method. Based on electron microscopical and histochemical findings, we conjectured that the focal cytoplasmic necrosis of the smooth muscle cells in the arterial media depended on injury arising from mitochondria-derived oxidants.
高血压大鼠的动脉表现出严重的中膜平滑肌细胞损伤和坏死。电镜观察显示，这些动脉的平滑肌细胞具有局灶性细胞质坏死的特征，在健康细胞质和坏死细胞质之间形成新的细胞分界膜。当损伤的平滑肌细胞中的局灶性坏死细胞质消失时，它会留下类似虫蚀的叶片状外观（虫蚀样坏死）。在损伤的晚期，平滑肌细胞变成带有新形成基膜的胰岛样细胞体，进一步的胰岛样细胞体和细胞碎片消失，留下板层和网状基膜。在注射氮蓝四唑（NBT）的高血压大鼠中，在内膜细胞中观察到甲臜沉积物，并用免疫组织化学方法观察到动脉中膜的过氧亚硝酸盐生物标志物硝基酪氨酸。使用 DNA 缺口末端标记法在动脉中膜中检测到阳性核外小颗粒体，这些颗粒体可能来源于局灶性坏死细胞质和细胞核。基于电镜和组织化学发现，我们推测动脉中膜平滑肌细胞的局灶性细胞质坏死依赖于线粒体衍生的氧化剂引起的损伤。
