YAMADA E
J Biophys Biochem Cytol. 1955 Nov 25;1(6):551-66. doi: 10.1083/jcb.1.6.551.
Sections of mouse renal glomerulus fixed by perfusion with buffered osmium tetroxide solution have been studied with the electron microscope. Four components are recognized in the mouse glomerulus: epithelium, basement membrane, endothelium, and intercapillary cell. The three cellular components all display in their cytoplasm mitochondria, Golgi bodies, endoplasmic reticulum, and uncharacterized vesicles. The concepts of Hall, of Pease, and of Rhodin regarding the glomerular filtration surface are confirmed. The epithelial cells are characterized by intricate, branching, interdigitating ridge-like processes or pedicels, the summits of which press against the urinary surface of the basement membrane, covering the glomerular capillary tuft almost completely except for narrow spaces about 200 to 300 A wide between the processes. These spaces are termed the epithelial filtration slits, and are bridged by a very delicate gossamer-like membrane about 30 A thick,-the filtration slit membrane. The basement membrane is interposed everywhere between epithelial processes and endothelium, and between epithelial and intercapillary cells. The basement membrane of the filtration surface of the glomerular capillary has smooth surfaces and is about 800 A thick. It consists of three layers-a thick central lamina densa, appearing to have a very delicate felt-like structure, flanked on each side by thinner lamina rara externa and lamina rara interna. This membrane continues to the intercapillary space and makes a complicated sponge-work of varying thickness in which the intercapillary cells are enmeshed. The endothelial cells are of moderate thickness in the nuclear region, but send out thin sheet-like extensions over the filtration surface. These extensions are about 300 to 400 A thick and are characterized by numerous round endothelial filtration pores about 500 to 1000 A in diameter. The intercapillary tissue or mesangium is composed of the network of the basement membrane and the intercapillary cells. The intercapillary cells, with characteristic fine fibrillar cytoplasm, make contact with epithelial and endothelial cells and are enmeshed within the network of the basement membrane. Rounded processes of intercapillary cells penetrate into the endothelial cell through the basement membrane, and may even perforate entirely through the endothelium. Such processes are called (after Zimmermann) the intracapillary colliculi. In the endothelial cytoplasm close to the intracapillary colliculi are many dense endothelial juxtacollicular vesicles and caveolae. The cell boundaries of the endothelial cell resemble terminal bars. Some physiological speculations relating to glomerular structure are advanced. The description of Zimmermann (54), based on a light microscope study, is confirmed in many respects.
用缓冲四氧化锇溶液灌注固定的小鼠肾肾小球切片已用电子显微镜进行了研究。在小鼠肾小球中可识别出四种成分：上皮细胞、基底膜、内皮细胞和毛细血管间细胞。三种细胞成分的细胞质中均有线粒体、高尔基体、内质网和未明确特征的小泡。霍尔、皮斯和罗丁关于肾小球滤过表面的概念得到了证实。上皮细胞的特征是具有复杂的、分支的、相互交错的脊状突起或足突，其顶端压在基底膜的尿表面上，几乎完全覆盖肾小球毛细血管丛，除了突起之间约200至300埃宽的狭窄间隙。这些间隙称为上皮滤过裂隙，由一层约30埃厚的非常纤细的薄纱样膜——滤过裂隙膜——桥接。基底膜无处不在地介于上皮突起与内皮细胞之间，以及上皮细胞与毛细血管间细胞之间。肾小球毛细血管滤过表面的基底膜表面光滑，约800埃厚。它由三层组成——一层厚的中央致密层，似乎具有非常纤细的毡样结构，两侧各有一层较薄的外疏松层和内疏松层。该膜延续至毛细血管间间隙，并形成厚度各异的复杂海绵状结构，毛细血管间细胞陷入其中。内皮细胞在核区厚度适中，但在滤过表面发出薄片状延伸。这些延伸约300至400埃厚，其特征是有许多直径约500至1000埃的圆形内皮滤过孔。毛细血管间组织或系膜由基底膜网络和毛细血管间细胞组成。毛细血管间细胞具有特征性的细纤维状细胞质，与上皮细胞和内皮细胞接触，并陷入基底膜网络内。毛细血管间细胞的圆形突起通过基底膜穿入内皮细胞，甚至可能完全穿透内皮。这种突起（以齐默尔曼的命名）称为毛细血管内小丘。在靠近毛细血管内小丘的内皮细胞质中有许多密集的内皮近小丘小泡和小窝。内皮细胞的细胞边界类似终末棒。提出了一些与肾小球结构有关的生理学推测。齐默尔曼（54）基于光学显微镜研究的描述在许多方面得到了证实。
