MACROMOLECULAR TRANSPORT IN THE FETAL-RAT INTESTINE
MACROMOLECULAR TRANSPORT IN THE FETAL-RAT INTESTINE
复制标题
DOI：
10.1016/0016-5085(85)90329-4
复制
发表时间：
1985-01-01
期刊：
影响因子：
29.4
通讯作者：
NEUTRA, MR
中科院分区：
文献类型：
--
作者：
COLONY, PC;NEUTRA, MR
从妊娠16至22天（出生）分析胎鼠小肠和结肠的大分子屏障功能。在此期间，上皮由复层上皮转变为单层柱状上皮。为了评估渗透性，通过显微注射将辣根过氧化物酶（HRP）引入管腔或脐循环。近端小肠，远端小肠和结肠进行了检查后，10-20分钟。通过闭塞连接的HRP细胞旁通道后，无论是腔内或血管内注射没有观察到。在管腔内注射后，HRP从管腔到血液的经上皮转运发生在所有研究年龄的所有区域。辣根过氧化物酶存在于原始复层上皮、上皮转化和单纯柱状上皮中大多数细胞的胞质小泡中。血管内注射后，HRP存在于固有层和上皮细胞间隙，但HRP没有进入紧密连接。在复层和单层柱状上皮细胞的胞质囊泡中均可摄取示踪剂，但在管腔中很少见到示踪剂。我们的结论是：（a）有快速的跨细胞，囊泡介导的运输从管腔到血液中的分层和简单的柱状上皮细胞的胎鼠小肠和结肠;（B）血管内注射后，大分子可能会采取到囊泡在基底外侧上皮细胞表面，但不迅速运输到管腔;（c）旁细胞通道不发生在胎龄研究。
Macromolecular barrier function of the fetal rat small intestine and colon was analyzed from 16 to 22 days gestation (birth). During this period the epithelium is converted from stratified to simple columnar. To assess permeability, horseradish peroxidase (HRP) was introduced by microinjection into the lumen or into the umbilical circulation. Proximal small intestine, distal small intestine, and colon were examined after 10-20 min. Paracellular passage of HRP through occluding junctions was not observed after either intraluminal or intravascular injection. After intraluminal injection, transepithelial transport of HRP from lumen to blood occurred in all regions at all ages studied. Horseradish peroxidase was present in cytoplasmic vesicles of most cells in the primitive stratified epithelia, during epithelial conversion, and in simple columnar epithelia. After intravascular injection, HRP was present in the lamina propria and in intercellular spaces of the epithelium, but HRP did not enter tight junctions. Tracer was taken up into cytoplasmic vesicles of both stratified and simple columnar epithelial cells, but was only rarely seen in the lumen. We conclude that (a) there is rapid transcellular, vesicle-mediated transport from lumen to blood across both stratified and simple columnar epithelia of fetal rat small intestine and colon; (b) after intravascular injection, macromolecules may be taken up into vesicles at basolateral epithelial cell surfaces but are not rapidly transported into the lumen; (c) paracellular passage does not occur in the fetal ages studied.