Allan C H, Trier J S
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
Gastroenterology. 1991 May;100(5 Pt 1):1172-9.
Intravenously injected sheep antilaminin immunoglobulin G conjugated with horseradish peroxidase uniformly labeled the basement membrane of mouse villus epithelium but not that of Peyer's patch follicle domes, although laminin is abundant in both. This suggested differences in the permeability of capillaries underlying these epithelia. Therefore, the fine structure of mouse subepithelial villus and follicle capillaries and their permeability to selected macromolecules was compared. Fenestrae, abundant in villus capillaries, were extremely rare in dome capillaries as assessed by electron microscopy of tissue sections and freeze-fracture replicas. Two minutes after IV-injected horseradish peroxidase and 9 minutes after IV-injected hemoglobin, reaction product decorated the pericapillary space of 97% and 95%, respectively, of capillary profiles in the upper half of villi but only 28% and 2%, respectively, of capillary profiles in the upper half of patch domes. Reaction product was intense surrounding most villus capillaries but, when present, was faint in dome capillary adventitia. These results indicate that most subepithelial capillaries in mouse Peyer's patch domes, unlike those in villi, generally lack endothelial fenestrae, and the dome capillary network is less permeable to some macromolecules than that of the villus.
静脉注射与辣根过氧化物酶偶联的羊抗层粘连蛋白免疫球蛋白G，能使小鼠绒毛上皮的基底膜均匀着色，但不能使派尔集合淋巴结滤泡圆顶的基底膜着色，尽管这两种结构中都富含层粘连蛋白。这表明这些上皮下方的毛细血管通透性存在差异。因此，对小鼠绒毛和滤泡圆顶上皮下毛细血管的精细结构及其对特定大分子的通透性进行了比较。通过组织切片和冷冻蚀刻复制品的电子显微镜观察评估，发现绒毛毛细血管中丰富的窗孔在圆顶毛细血管中极为罕见。静脉注射辣根过氧化物酶2分钟后以及静脉注射血红蛋白9分钟后，反应产物分别出现在绒毛上半部分97%和95%的毛细血管轮廓的毛细血管周围间隙中，但在圆顶滤泡上半部分的毛细血管轮廓中分别仅为28%和2%。反应产物在大多数绒毛毛细血管周围强烈，但在圆顶毛细血管外膜中（若存在）则很微弱。这些结果表明，与绒毛中的毛细血管不同小鼠派尔集合淋巴结滤泡圆顶中的大多数上皮下毛细血管通常缺乏内皮窗孔，并且圆顶毛细血管网络对某些大分子的通透性低于绒毛的毛细血管网络。
