Guyton J R, Klemp K F
Department of Medicine and Cell Biology, Baylor College of Medicine, Methodist Hospital, Houston, Texas 77030.
Am J Pathol. 1989 Mar;134(3):705-17.
Abundant extracellular lipid deposits are associated with cell necrosis and tissue weakening in the core region of human atherosclerotic fibrous plaques. The ultrastructural morphology of the core region, previously undefined because of lipid extraction artifacts, was studied with the aid of new osmium-thiocarbohydrazide-osmium and osmium-tannic acid-paraphenylenediamine sequences for tissue processing. Small droplets of neutral lipid (30 to 400 nm profile diameter) and lipid vesicles with aqueous centers accounted for more than 90% of the area occupied by lipid-rich structures in the core region. No foam cells were present. Cholesterol crystals, lipid droplets of a size similar to those in foam cells (0.4 to 6 mu), and larger neutral lipid deposits (greater than 6 mu) together occupied less than 10% of the total area of lipid structures. Abundant lipid vesicles were associated with the nearby presence of cholesterol crystals, whereas small lipid droplets were predominant in areas without crystals. Many droplets had surface defects in the form of pits and vesicular blebs. These morphologic findings are explained most concisely by postulating direct accumulation of extracellular lipid from interstitial lipoproteins as a major process in core region formation. Moreover, a dynamic state of ongoing physical/metabolic transformation of extracellular lipid deposits is suggested.
在人类动脉粥样硬化纤维斑块的核心区域，大量细胞外脂质沉积与细胞坏死和组织弱化相关。由于脂质提取假象，核心区域的超微结构形态此前未明确，借助用于组织处理的新锇-硫代碳酰肼-锇和锇-单宁酸-对苯二胺序列对此进行了研究。中性脂质小滴（轮廓直径30至400纳米）和具有水性中心的脂质小泡占核心区域富含脂质结构所占面积的90%以上。不存在泡沫细胞。胆固醇晶体、大小与泡沫细胞中的脂质小滴相似（0.4至6微米）的脂质小滴以及较大的中性脂质沉积物（大于6微米）共同占脂质结构总面积的不到10%。大量脂质小泡与附近存在的胆固醇晶体相关，而小脂质小滴在无晶体区域占主导。许多小滴有凹坑和囊泡状小泡形式的表面缺陷。通过假定细胞外脂质从间质脂蛋白直接积累作为核心区域形成的主要过程，能最简洁地解释这些形态学发现。此外，提示细胞外脂质沉积物存在持续的物理/代谢转化动态状态。
