1994 Fiscal Year Final Research Report Summary
A novel mechanism on disposing of effete enterocytes
| Project/Area Number |
05670003
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Niigata University |
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Principal Investigator |
IWANAGA Toshihiko Niigata University School of Medicine Assoc.Prof., 医学部, 助教授 (10160128)
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| Co-Investigator(Kenkyū-buntansha) |
IWANAGA Hiromi Niigata University School of Medicine Lecturer, 医学部, 講師 (30193759)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Enterocytes / Apoptosis / Lymphocytes / Macrophages |
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| Research Abstract |
1. Effete epithelial cells in the small intestine of the guinea pig, major parts of cell bodies, are phagocytosed by lamina propria macrophages. However, the apical cytoplasm remain within the epithe lium after the apoptotic event. The present study demonstrated that the skin-like apical cytoplasm is connected with adjacent enterocytes by junctional complexes, still keeping the epithelial barrier.
2. The apical cytoplasm with the brush border is protruded into the luminal space due to closing of adjacent cells, and pinched off into the lumen when the adjacent cells contacted. During the process, no holes of the epithelium were recognizable. Thereafter, there were numerous cytoplasmic fragments with the brush border in the lumen of intestine.
3. In the rat, the intestinal lumen contained numerous cell bodies of apoptotic enterocytes with nuclei, suggesting exfoliation of whole cell bodies into the lumen.
4. The guines pig-type mechanism on disposing of effete epithelial cells was recognized in the monkey and horse, while the rat-type mechanism was shared by the mouse. Humans were basically classified into the latter type.
5. Cell death of enterocytes may not be soley programd cell death, but easily induced by external factors. Intraepithelial lymphocytes are involved in the induction of apoptosis in the guinea pig, while in the rat lamina propria macrophages participate in this mechanism.
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