Letter to the Editor
Letter to the Editor
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DOI：
10.1354/vp.44-6-963
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发表时间：
2007-11
影响因子：
2.4
通讯作者：
J. Riley
中科院分区：
文献类型：
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作者：
J. Riley
由于几个原因，上述假设是不成立的。颊囊是一种特殊的结构，内衬有一层相对较厚的表面角蛋白，位于角质层、复层鳞状上皮之上：基本上像表皮，但缺乏树突状细胞和附属结构，如粘液腺。后颊囊上皮与舌、牙龈和硬腭的上皮相似，但缺少相同数量的常驻树突状细胞和分泌腺。未角化的复层鳞状上皮排列在口腔的其余部分。角质化的，多层的，囊上皮耐磨损，阻碍吸收，使仓鼠储存未消化的食物的形式，水果，坚果，浆果和昆虫在他们的邮袋。囊外膜相当致密，缺乏粘附性，主要用于粘附上皮。胃肠道的某些部分衬有粘膜。单层上皮为柱状或低柱状，其间分布有分泌粘液的腺体和其它腺体。表面粘液，其名称的来源，提供对化学品的保护，并作为润滑剂。肠道的粘液表面具有吸收性。在小肠中，有专门的精致微绒毛专门用于此目的。粘膜含有派尔斑和其他免疫监视，如上皮内淋巴细胞。上皮细胞下有丰富的神经、血液和淋巴管系统，支持分泌、吸收和免疫监视活动。考虑到上述所有因素，也许最重要的是仓鼠颊囊是一个免疫保护部位，将其用作胃肠道和口腔粘膜的替代品似乎并不十分引人注目。具有完整免疫监视和更易于评估的表皮较薄区域可能是替代物的更好选择。不幸的是，这两个部位都有不是粘膜的缺点。皮肤上的疼痛性病变不会像颊囊上的疼痛性病变那样影响食物的摄入-这当然是皮肤部位的优势。.朱莉娅·H Riley，MS .Diplomate American College Veterinary Pathologists .美国毒理学委员会文凭
For several reasons the above assumption is not valid. Hamster cheek pouches are specialized structures lined with a relatively thick layer of surface keratin lying above cornified, stratified squamous epithelium: essentially like the epidermis, but lacking dendritic cells and adnexal structures such a mucous glands. Hamster cheek pouch epithelium is similar to that of the tongue, gingiva and hard palate but lacks equal numbers of resident dendritic cells and secretary glands. Unkeratinized stratified squamous epithelium lines the remainder of the oral cavity. The keratinized, multiple-layered, pouch epithelium is resistant to abrasion and hinders absorption, allowing hamsters to store undigested food in the form of fruits, nuts, berries and insects in their pouches. Pouch adventitia is rather dense, lacking lymphatics and serving mainly to adhere the epithelium. Mucosa lines some parts of the gastrointestinal tract. The single-layer of epithelium is columnar or low columnar and is interspersed with mucus-secreting and other glands. Surface mucus, for which the name is derived, provides protection against chemicals and acts as a lubricant. Mucosal surfaces of the gut are absorptive. In the small intestine, there are specialized delicate microvilli dedicated to this purpose. Mucosa contains Peyer’s patches and other immune surveillance such as intraepithelial lymphocytes. A rich system of nerves, blood, and lymph vessels underlies the epithelium supporting the secretary, absorptive and immune surveillance activity. Given all of the above and perhaps most importantly the fact that the hamster cheek pouch is an immunologically protected site, use as a surrogate for the gastrointestinal and oral mucosa does not seem very compelling. Thinner areas of the epidermis with intact immunological surveillance and greater ease of access for evaluation may be a better choice as surrogates. Both sites unfortunately suffer the disadvantage of not being mucous membranes. Painful lesions in the skin do not interfere with food intake to the same extent as those in the cheek pouch– certainly an advantage of the skin site. . Julia H. Riley, MS .Diplomate American College Veterinary Pathologists . Diplomate American Board Toxicology