Zidan Mohamed, Pabst Reinhard
Department of Histology and Cytology, Faculty of Veterinary Medicine, Alexandria University, Egypt.
Anat Rec (Hoboken). 2008 Aug;291(8):1023-8. doi: 10.1002/ar.20697.
The Peyer's patches (PP) have been intensely investigated in several species because this is an important entry site for antigens and infectious agents. There are many PP in the jejunum, and in some species such as ruminants, carnivores, and omnivores, a different continuous PP is found in the terminal ileum. This PP disappears with age in these species studied. So far the ileal PP (IPP) has only been examined in the camel by light microscopy. Therefore, the localization of ileal Peyer's patches in the dromedary camel at different ages, as well as the histology and ultrastructures were now investigated. The IPP were characteristically seen as dark rose-colored isolated structures in the shape of a cup, arranged in three irregular rows. The central row was antimesenteric. Each patch was formed by several mainly elongated dome regions flanked by intestinal villi. In cross-sections these domes appeared as short, wide villi. The domes were formed from lymphoid follicles covered with a typical dome-associated epithelium of enterocytes and M cells without any goblet cells. The M cells showed variable appearance depending on the functional status. The lymphoid follicles expressed clear germinal centers. High endothelial venules were localized in the interfollicular region. In contrast to other species the IPP were still present with a comparable macroscopic and histological structure in camels of 25 years of age.
派尔集合淋巴结（PP）在多个物种中都受到了深入研究，因为它是抗原和感染因子的重要进入部位。空肠中有许多派尔集合淋巴结，在反刍动物、食肉动物和杂食动物等一些物种中，回肠末端还存在不同的连续派尔集合淋巴结。在所研究的这些物种中，这种派尔集合淋巴结会随着年龄增长而消失。到目前为止，仅通过光学显微镜在骆驼中检查过回肠派尔集合淋巴结（IPP）。因此，现在对单峰驼不同年龄段回肠派尔集合淋巴结的定位以及组织学和超微结构进行了研究。回肠派尔集合淋巴结的特征是呈杯状的暗玫瑰色孤立结构，排列成三排不规则的形状。中间一排位于肠系膜对侧。每个淋巴结由几个主要呈细长形的圆顶区域组成，两侧为肠绒毛。在横切面上，这些圆顶看起来像短而宽的绒毛。圆顶由淋巴滤泡形成，表面覆盖着一层典型的与圆顶相关的肠上皮细胞和M细胞上皮，没有任何杯状细胞。M细胞的外观因功能状态而异。淋巴滤泡有清晰的生发中心。高内皮微静脉位于滤泡间区域。与其他物种不同的是，25岁骆驼的回肠派尔集合淋巴结仍具有类似的宏观和组织结构。
