Gastrointestinal associated lymphoid tissue (GALT) is an important component of the mucosal immune system. It is the largest mass of lymphoid tissues in the body and makes up more than 70% immune cells of entire body. GALT is considered to be the origin of systemic mucosal immunity and consists of solitary lymphoid nodules, aggregated lymphoid nodules (Peyer's patches, PPs), scattered lymphoid tissues, and follicular associated epithelia. PPs play important roles as antigen inductive sites of the mucosal immune system, which are mainly distributed in the intestine of animals and humans (especially ileum and appendix). However, a special area of well-developed aggregated lymphoid nodules in the abomasum of Dromedary camel was found in our laboratory. Its existence was rarely described in the stomach before. In the present study, we investigated this special structure with the dromedary camels of different ages (young, 0.5-2 years; pubertal, 3-5 years; middle-aged, 6-16 years; old, 17-20 years), by the anatomical, histological and immunohistochemical approaches. The results showed that the special structure was mainly distributed in the cardiac glandular area of the abomasum, forming a triangular area. The mucosal folds in this area were significantly thicker than those in the surrounding region. These mucosal folds had two different forms, namely reticular mucosal folds (RMF) and longitudinal mucosal folds (LMF). There were abundant lymphoid nodules in the submucosa of RMF and LMF, which were arranged in one or multiple rows. The statistical analysis of the height and thickness of RMF and LMF showed that the structure was most developed in pubertal dromedary camels. The histological characteristics of the structure were the same as PPs in the intestine of the Dromedary camel, while anatomical appearance showed some difference. The immunohistochemical examination revealed that both immunoglobulin A (IgA) and G (IgG) antibodies-producing cells (APCs) were extensively distributed in the gastric lamina propria (LP) in all age group. Our finding suggest that camel stomach not only performs digestive functions, but also involves parts of body immunity.

中文翻译：

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单峰骆驼 (Camelus Dromedarius) 胃中聚集的淋巴结节的解剖学和组织学特征的年龄依赖性变化。

胃肠道相关淋巴组织（GALT）是粘膜免疫系统的重要组成部分。它是体内最大的淋巴组织，占全身免疫细胞的70%以上。GALT 被认为是全身粘膜免疫的起源，由孤立的淋巴结节、聚集的淋巴结节（Peyer's patches，PPs）、散在的淋巴组织和滤泡相关的上皮细胞组成。PPs作为粘膜免疫系统的抗原诱导位点起着重要作用，主要分布在动物和人类的肠道（尤其是回肠和阑尾）。然而，我们实验室在单峰骆驼的皱胃中发现了一个发育良好的聚集淋巴结节的特殊区域。它的存在，以前在肚子里很少被描述过。在目前的研究中，我们用不同年龄（年轻，0.5-2 岁；青春期，3-5 岁；中年，6-16 岁；老年，17-20 岁）的单峰骆驼研究了这种特殊结构，通过解剖学、组织学和免疫组化方法。结果表明，这种特殊结构主要分布在真胃心腺区，形成一个三角形区域。该区域的粘膜皱襞比周围区域的粘膜皱襞明显厚。这些粘膜皱襞有两种不同的形式，即网状粘膜皱襞（RMF）和纵向粘膜皱襞（LMF）。RMF和LMF粘膜下层有丰富的淋巴结，排列成一排或多排。对RMF和LMF的高度和厚度进行统计分析表明，该结构在青春期单峰骆驼中最为发达。该结构的组织学特征与单峰骆驼肠道中的PPs相同，而解剖学外观则有一定差异。免疫组织化学检查显示，免疫球蛋白 A (IgA) 和 G (IgG) 抗体产生细胞 (APC) 广泛分布于所有年龄组的胃固有层 (LP)。我们的研究结果表明，骆驼胃不仅具有消化功能，还涉及身体的部分免疫功能。