1998 Fiscal Year Final Research Report Summary
The role of vascular nets in intestinal villi formation.
| Project/Area Number |
09670032
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | JIKEI UNIVERSITY SCHOOL OF MEDICINE |
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Principal Investigator |
HASHIMOTO Hisashi JIKEI UNIVERSITY SCHOOL OF MEDICINE,DEPARTMENT OF ANATOMY,ASSISTANT PROFESSOR, 医学部, 助教授 (80189498)
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| Project Period (FY) |
1997 – 1998
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| Keywords | small intestine / villi formatation / capillary nets / fluorochrome-labelled gelatin / confocal laser scanning microscopy / three dimensional reconstruction / methotrexate |
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| Research Abstract |
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.
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