ENDOCYTOSIS AND VESICULAR TRAFFIC IN FETAL AND ADULT COLONIC GOBLET CELLS
ENDOCYTOSIS AND VESICULAR TRAFFIC IN FETAL AND ADULT COLONIC GOBLET CELLS
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DOI：
10.1002/ar.1092180403
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发表时间：
1987-08-01
影响因子：
--
通讯作者：
SPECIAN, RD
中科院分区：
文献类型：
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作者：
COLONY, PC;SPECIAN, RD
成人和胎儿结肠杯状细胞之间的结构和功能差异尚未明确定义。为了比较胎儿和成人杯状细胞内化顶膜的结合、摄取和细胞内途径，使用阳离子铁蛋白（CF）作为非特异性探针。在胎儿（18-22天）和成年大鼠的近端和远端结肠段中确定膜阴离子位点的初始分布，这些片段在4°C下暴露于CF 10分钟之前被固定。 C.在所有年龄段都注意到沿顶膜和微绒毛的均匀结合。为了评估摄取和细胞内转运，将胎儿和成年大鼠的近端和远端结肠段在4°C下暴露于CF 10分钟，然后进行盐水洗涤并在盐水或Liebovitz L-15培养基中在37°C下孵育3、6、15、30或60分钟。 C.此外，将妊娠18至22天（出生）的胎鼠通过盲肠内注射连续暴露于CF 10-30分钟。结果显示，胎儿杯状细胞广泛摄取 CF，并且细胞内途径比成人的变化更多。 3分钟内，胎儿杯状细胞的顶端细胞质内出现大量CF阳性囊泡和小管，并散布在分泌颗粒中。大多数这些囊泡表面光滑，尽管有些囊泡有涂层。 15分钟时，CF经常出现在多泡体中，偶尔出现在高尔基体附近的空泡中。高尔基池中未检测到 CF。与胎儿细胞相反，在成年杯状细胞中仅观察到有限的摄取，并且囊泡仅限于分泌颗粒团的外围。此外，运输到溶酶体是这些囊泡在成人体内的唯一途径。这些发现表明，胎儿杯状细胞中的囊泡摄取广泛，并且细胞内途径比成人的变化更大且限制更少。
Structural and functional differences between adult and fetal colonic goblet cells have not been clearly defined. To compare the binding, uptake and intracellular pathway of internalized apical membrane in fetal and adult goblet cells, cationic ferritin (CF) was used as a nonspecific probe. The initial distribution of membrane anionic sites was determined in segments of proximal and distal colon from fetal (18-22 days) and adult rats that were fixed prior to a 10-minute exposure to CF at 4.degree. C. Uniform binding along the apical membrane and microvilli was noted at all ages. To assess uptake and intracellular transport, segments of proximal and distal colon from fetal and adult rats were exposed to CF for 10 minutes at 4.degree.C prior to a saline wash and incubation in saline or Liebovitz L-15 medium for 3, 6, 15, 30, or 60 minutes at 37.degree. C. In addition, fetal rats between 18 and 22 days gestation (birth) were exposed to CF continuously for 10-30 minutes via an intracaecal injection. The results showed extensive uptake of CF in the fetal goblet cells and a more variable intracellular pathway than in with the adult. Within 3 minutes, numerous CF positive vesicles and tubules were present within the apical cytoplasm as well as interspersed among the secretory granules of the fetal goblet cell. Most of these vesicles were smooth surfaced, although some were coated. By 15 minutes, CF was frequently seen in multivesicular bodies, and occasionally in vacuoles in the vicinity of the Golgi. No CF was detected in Golgi cisternae. In contrast to fetal cells, only limited uptake was noted in adult goblet cells and the vesicles were restricted to the periphery of the secretory granule mass. In addition, transport to lysosomes was the exclusive route of these vesicles in the adult. These findings indicate that vesicular uptake is extensive in fetal goblet cells and the intracellular pathway is more variable and less restricted than in the adult.