Milici A J, Peters K R, Palade G E
Cell Tissue Res. 1986;244(3):493-9. doi: 10.1007/BF00212526.
A new endothelial cell structure, named the endothelial pocket, has been found by combined transmission and scanning electron microscopic studies of renal peritubular capillaries. Transmission EM observations made on these and other fenestrated capillaries demonstrated that each pocket consists of an attenuated fold of fenestrated endothelium that projects approximately 200 nm into the lumen above the rest of the endothelial surface. Beneath this luminal fold, there is a space and then another layer of fenestrated endothelium which abuts the basal lamina. The linear density of endothelial pockets was measured in the capillaries of the kidney cortex, intestinal mucosa and exocrine pancreas in mice and determined to be 0.067, 0.017 and 0.007 pockets X micron-1 respectively. Cationic ferritin decoration of the anionic sites on the luminal surface of the endothelium in these capillary beds revealed that both unlabelled and labelled diaphragms are clustered. In such specimens, the majority of the luminal diaphragms on endothelial pockets did not have cationic ferritin binding sites detectable by either scanning or transmission EM. On this account as well as on account of their general morphology, endothelial pockets appear to be multifold versions of the simple transendothelial channel.
通过对肾周毛细血管进行透射电子显微镜和扫描电子显微镜联合研究，发现了一种新的内皮细胞结构，称为内皮袋。对这些及其他有窗孔毛细血管的透射电镜观察表明，每个内皮袋由有窗孔内皮的变薄褶皱组成，该褶皱向管腔突出约200纳米，高于内皮表面的其他部分。在这个管腔褶皱下方，有一个间隙，然后是另一层与基膜相邻的有窗孔内皮。在小鼠肾皮质、肠黏膜和外分泌胰腺的毛细血管中测量了内皮袋的线密度，分别确定为0.067、0.017和0.007个内皮袋×微米-1。对这些毛细血管床内皮管腔表面阴离子位点进行阳离子铁蛋白标记显示，未标记和标记的隔膜都聚集在一起。在这类标本中，内皮袋上的大多数管腔隔膜在扫描电镜或透射电镜下均未检测到阳离子铁蛋白结合位点。基于这一点以及它们的一般形态，内皮袋似乎是简单跨内皮通道的多重形式。
