Karam S, Leblond C P
Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
Microsc Res Tech. 1995 Jun 15;31(3):193-214. doi: 10.1002/jemt.1070310304.
The secretions of the mammalian stomach are produced by cells present in invaginations of the epithelium, which in the mouse are straight tubules referred to as "zymogenic units." These units comprise four regions, namely pit, isthmus, neck, and base, in which there are several cell lineages with different phenotypes and migratory pathways. In the isthmus, stem cells designated "undifferentiated granule-free cells" undergo division so as to maintain their own number and produce several differently oriented progenitors: (1) "Pre-pit cell precursors" are characterized by prosecretory Golgi vesicles with a uniform, fine particulate content. They give rise to "pre-pit cells" defined by the presence of few dense mucous granules. These cells migrate outward from the isthmus to the pit, where they become the dense granule-rich "pit cells" which populate the pit region and migrate to the gastric surface where they are lost. (2) "Pre-neck cell precursors" are identified by prosecretory Golgi vesicles containing an irregular dense center and a light rim. They give rise to "pre-neck cells" defined by a few mucous secretory granules with a clear-cut core. These cells migrate inward from the isthmus to the neck where they become "neck cells," which contain many such granules. Even though neck cells are mature mucus-producers, they are not end cells. As they enter the base region, they become "prezymogenic cells" whose phenotype gradually changes from mucous to serous. These cells eventually lose the ability to produce mucus and thus become the typical zymogenic cells that populate the base region. (3) "Pre-parietal cells" are classified into three variants, which probably come from three different sources, that is, pre-pit cell precursors, pre-neck precursors, and the undifferentiated granule-free cells themselves. The preparietal cells mature into parietal cells which migrate either outward to the pit or inward to the neck and base. As a result, parietal cells are scattered in the four regions of the unit. (4) Precursors of "entero-endocrine" and "caveolated" cells give rise in the isthmus to these cells, which may also migrate outward or inward.
哺乳动物胃的分泌物由上皮内陷处的细胞产生，在小鼠中这些内陷是被称为“酶原单位”的直管。这些单位包括四个区域，即胃小凹、峡部、颈部和基部，其中有几种具有不同表型和迁移途径的细胞谱系。在峡部，被称为“未分化无颗粒细胞”的干细胞进行分裂以维持自身数量，并产生几种不同取向的祖细胞：（1）“胃小凹前体细胞前体”的特征是具有均匀、细小颗粒内容物的促分泌高尔基体囊泡。它们产生由少量致密黏液颗粒定义的“胃小凹前体细胞”。这些细胞从峡部向外迁移到胃小凹，在那里它们成为富含致密颗粒的“胃小凹细胞”，这些细胞填充胃小凹区域并迁移到胃表面并在那里消失。（2）“颈部前体细胞前体”通过含有不规则致密中心和浅色边缘的促分泌高尔基体囊泡来识别。它们产生由一些具有清晰核心的黏液分泌颗粒定义的“颈部前体细胞”。这些细胞从峡部向内迁移到颈部，在那里它们成为“颈部细胞”，颈部细胞含有许多这样的颗粒。尽管颈部细胞是成熟的黏液产生细胞，但它们不是终末细胞。当它们进入基部区域时，它们成为“前酶原细胞”，其表型逐渐从黏液型转变为浆液型。这些细胞最终失去产生黏液的能力，从而成为填充基部区域的典型酶原细胞。（3）“壁细胞前体”分为三种变体，它们可能来自三个不同的来源，即胃小凹前体细胞前体、颈部前体和未分化无颗粒细胞本身。壁细胞前体成熟为壁细胞，壁细胞要么向外迁移到胃小凹，要么向内迁移到颈部和基部。结果，壁细胞分散在该单位的四个区域中。（4）“肠内分泌”和“小窝状”细胞的前体在峡部产生这些细胞，这些细胞也可能向外或向内迁移。
