title: Pathogenesis of focal cytoplasmic necrosis of the smooth muscle cells in hypertensive rat arterial media.
abstract: 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.
authors: Geriatrics Research Institute , Maebashi, Gunma 371-0847, Japan.
authors: Keiji
authors: K
authors: Suzuki
authors: Second Department of Pathology, Fukuoka University School of Medicine , Fukuoka 814-0180, Japan.
authors: Noriyuki
authors: N
authors: Sakata
authors: AdaBio Co., Ltd. , 21-2 Kenzaki Machi, Takasaki, Gunma 370-0883, Japan.
authors: Katsuya
authors: K
authors: Hiraishi
authors: Department of Pathology, Mita Hospital International University of Health and Welfare , 1-4-3, Mita, Minato-ku, Tokyo 108-8329, Japan.
authors: Ichiro
authors: I
authors: Mori
authors: Geriatrics Research Institute , Maebashi, Gunma 371-0847, Japan.
authors: Masamitsu
authors: M
authors: Takatama
keywords: arterial injury; focal cytoplasmic necrosis; hypertension; mitochondria-derived oxidant; smooth muscle cell necrosis