Nishio S, Ohta M, Abe M, Kitamura K
Acta Neuropathol. 1983;59(1):1-10. doi: 10.1007/BF00690311.
The fine structure, histometric characteristics, and permeability of microvessels were studied by electron microscopy in normal and in ethylnitrosourea (ENU)-induced glioma tissue from rats, using horseradish peroxidase (HRP) as a tracer. The tumor vessels were classified into (1) capillary buds (Type I); (2) round small to large capillaries (Type II); (3) sinusoidal or venule-like microvessels (Type III), and (4) abnormal arteriole-like microvessels (Type IV). All endothelial cells, basement membranes and periendothelial cells in the tumor tissue demonstrated changes in structure. The most striking alterations occurred in the endothelial cells; there were abnormal endothelial tight junctions, altered pinocytotic activity, and thickening. In the tracer study, the reaction product of HRP was present around some sinusoidal or venule-like microvessels (Type III) and extended to the widened extracellular spaces around the microvessels. The endothelial cells of Type III microvessels showed decreased nuclear and mitochondrial fractions, and increased euchromatin content and a rough endoplasmic reticulum fraction. The pinocytotic vesicles with the HRP reaction product in the endothelial cells were not increased in number. Fenestrations and gaps of the endothelial cells were observed. These alterations of the endothelial cells of sinusoidal or venule-like microvessels (Type III) are considered to be the main cause of breakdown of the blood-brain barrier in this tumor.
采用辣根过氧化物酶（HRP）作为示踪剂，通过电子显微镜研究了正常大鼠和乙基亚硝基脲（ENU）诱导的大鼠胶质瘤组织中微血管的精细结构、组织计量学特征和通透性。肿瘤血管分为：（1）毛细血管芽（I型）；（2）圆形的小至大毛细血管（II型）；（3）窦状或小静脉样微血管（III型）；以及（4）异常的小动脉样微血管（IV型）。肿瘤组织中的所有内皮细胞、基底膜和周内皮细胞均表现出结构变化。最显著的改变发生在内皮细胞；存在异常的内皮紧密连接、改变的胞饮活性和增厚。在示踪剂研究中，HRP的反应产物出现在一些窦状或小静脉样微血管（III型）周围，并延伸至微血管周围增宽的细胞外间隙。III型微血管的内皮细胞显示核和线粒体比例降低，常染色质含量增加，粗面内质网比例增加。内皮细胞中带有HRP反应产物的胞饮小泡数量未增加。观察到内皮细胞的窗孔和间隙。窦状或小静脉样微血管（III型）内皮细胞的这些改变被认为是该肿瘤血脑屏障破坏的主要原因。
