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The role of vascular nets in intestinal villi formation.

血管网在肠绒毛形成中的作用。

基本信息

批准号：
09670032
负责人：
HASHIMOTO Hisashi
金额：
$ 1.73万
依托单位：
JIKEI UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

The initial formation of intestinal villi in the mouse was investigated in association with the development of vascular networks. On 12 and 13 days of gestation, the small intestine and its epithelium formed cylindrical tube and a loose plexus of vessels was builded in the mesenchyme. In the small intestine of 14 days of gestations, a dense plexus of smaller vessels was formed inside of the loose plexus and some branches from the former were placed beneath the epithelium. The epithelium began to make an ingrowth between the branches. An extension of the lumen had penetrated in the epithelium of the ingrowth to make it mostly simplified. Approximately half of the epithelial and mesenchymal cell incorporated BrdU for 2hr labelling. The labelled cell was prominent in the epithelium of the ingrowth and in the mesenchyme adjoining it. On 15 days of gestation, the ingrowth proceeded and lots of its epithelial cells were labelled with BrdU.The concavity between ingrowths deepened and formed an initial villus. The capillary branch formed a loop and extended into the villus as far as the top of the villus. As the development proceeded, the villus elongated and the capillary loop also extended. The top of the capillary loop always kept it position of the top of the villus. Administration of methotrexate before 14 days of gestation frequently disturbed the viii formation. After 15 days of gestation, the density of the villus was rarely affected by methotrexate administration. These results suggest that the initial formation of intestinal villi in the fetal mouse is performed by the ingrowth of the epithelium and that inhibition of cell proliferation before the villi formation disturbs it. The developing vascular nets would play some roles during the villi formation.

研究了小鼠小肠绒毛的初始形成与血管网发育的关系。妊娠12、13天，小肠及其上皮形成圆筒状管，间充质内形成疏松的血管丛。在14日龄的小肠中，在松散的血管丛内形成了一个由小血管组成的密集的血管丛，并有一些来自前者的分支位于上皮之下。上皮细胞开始向内生长。管腔的延伸部分已穿透向内生长的上皮，使其大部分简化。大约一半的上皮细胞和间充质细胞掺入BrdU进行2小时标记。标记细胞主要分布于内生长的上皮细胞及其周围的间充质细胞中，妊娠15天，内生长开始，大量上皮细胞被BrdU标记，内生长细胞间的缝隙加深，形成了最初的绒毛。毛细血管分支形成一个袢，并延伸到绒毛的顶部。随着发育的进行，绒毛延长，毛细血管袢也延长。毛细血管袢的顶端始终保持在绒毛顶端的位置。妊娠14天前给予甲氨蝶呤经常干扰viii的形成。妊娠15天后，绒毛密度很少受到甲氨蝶呤给药的影响。这些结果表明，胎鼠小肠绒毛的形成是由上皮细胞的向内生长完成的，在绒毛形成之前抑制细胞增殖会干扰绒毛的形成，发育中的血管网在绒毛形成过程中可能起一定作用。