ORIGIN, DIFFERENTIATION AND RENEWAL OF 4 MAIN EPITHELIAL-CELL TYPES IN MOUSE SMALL INTESTINE .1. COLUMNAR CELL
ORIGIN, DIFFERENTIATION AND RENEWAL OF 4 MAIN EPITHELIAL-CELL TYPES IN MOUSE SMALL INTESTINE .1. COLUMNAR CELL
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DOI：
10.1002/aja.1001410403
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发表时间：
1974-01-01
影响因子：
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通讯作者：
LEBLOND, CP
中科院分区：
文献类型：
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作者：
CHENG, H;LEBLOND, CP
本文用光镜、电子显微镜和放射自显影技术，观察了单次注射或连续注射~3H-胸腺嘧啶后不同时间处死的小鼠十二指肠、空肠和回肠的柱状细胞，即既不含粘液小球，又不含肠内分泌颗粒，也不含Panet型分泌物的细胞。柱状细胞有局部差异，可分为四个亚类：(A)隐窝基底部柱状细胞是平均占据隐窝最低9个细胞位置的未成熟增殖细胞。(B)隐窝中柱状细胞在回肠最多占据19个位置，在其他部位最多占据27个位置；它们增殖，并表现出从靠近底部的未分化细胞逐渐转变为较高位置的部分分化细胞的特征。(C)墓穴顶部的柱状细胞占据了墓穴的其余部分；它们不分裂，但继续分化。(D)绒毛柱状细胞为完全分化的吸收细胞，隐窝基端和隐窝中段柱状细胞在分裂前摄取~3H-胸腺嘧啶核苷标记。随着注射~3H-胸腺嘧啶核苷后时间的延长，其标记强度降低，而重度标记的柱状细胞在6小时后出现在隐窝顶部，在绒毛上出现12小时以上。因此，柱状细胞迁移。这种迁移与未成熟的隐窝基柱状细胞逐渐分化成成熟的绒毛柱状细胞有关。柱状细胞占上皮细胞的绝大部分(十二指肠、空肠和回肠分别为95%、94%和89%)。因此，它们很可能在小肠三个区域的上皮更新中发挥关键作用。根据连续输注的结果，柱状细胞的周转时间在十二指肠为3.3天，在空肠为3.4天。周转时间数据表明，柱状细胞的有丝分裂产生的细胞多于其自身更新所需的细胞。据推测，一些有丝分裂产生了柱状以外的细胞。
The columnar cells, i.e., the cells which contain neither mucous globules, nor entero‐endocrine granules, nor Paneth type secretion, were investigatedindependently of other cellsin duodenum, jejunum and ileum using light and electron microscopy as well as radioautography in mice sacrificed at various times after single injection or continuous infusion of3H‐thymidine.The columnar cells exhibit local differences allowing their classification into four sub‐groups: (a)The crypt‐base columnar cellsare immature proliferative cells occupying the nine lowest cell positions of the crypt on the average. (b)The mid‐crypt columnar cellsoccupy the next positions up to 19 in ileum and 27 elsewhere; they proliferate and show features gradually changing from undifferentiated ones near the base to partially differentiated ones higher up. (c)The crypt‐top columnar cellsoccupy the rest of the crypt; they do not divide but they continue to differentiate. (d) Finally, thevillus columnar cellsare fully differentiated absorptive cells.Cryp‐base and mid‐crypt columnar cells take up3H‐thymidine label prior to division. With time after a3H‐thymidine injection, the intensity of their labeling decreases, while heavily labeled columnar cells appear in crypt‐top by six hours and on the villus by 12 and more hours. Hence, columnar cells migrate. The migration is associated with gradual differentiation from the immature crypt‐base columnar cells to the mature villus columnar cells. The latter eventually reach the villus tips where they drop into the lumen.The columnar cells constitute a large majority of the epithelial cells (95, 94 and 89% in duodenum, jejunum and ileum, respectively). Hence, they are likely to play a key role in the renewal of the epithelium in the three regions of the small intestine. The turnover time of columnar cells estimated from results of continuous3H‐thymidine infusion is 3.3 days in duodenum and 3.4 days in jejunum.Evidence from turnover time data indicates that the mitoses of columnar cells produce more cells than required for their own renewal. Presumably some of the mitoses give rise to cells of a type other than columnar.