The relationship between ionizing radiation-induced apoptosis and stem cells in the small and large intestine.
AffiliationEpithelial Biology CRC Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK.
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AbstractApoptosis is observed in the crypts of the small intestine of healthy animals and man (spontaneous apoptosis). The levels can be dramatically elevated 3-6 h following ionizing radiation exposure. Both the spontaneous and radiation-induced apoptosis in the small intestine crypts are most frequently observed at the positions in the crypt associated with stem cells (about four cell positions from the base of the crypt). The number of apoptotic deaths can be counted in routine histological preparations, but interpretation of the counts is complicated by numerous factors. However, recording the number of cells containing one or more apoptotic fragments in crypt sections provides a good estimate for the absolute number of cell deaths in crypts. Similarities are noted in the frequency and cell positional relationship of radiation-induced apoptosis in the small intestine of various strains of mice and one strain of rat. Apoptosis in the large intestine is generally lower in frequency than in the small intestine and, for the mid-colonic and rectal regions, has a different cell positional frequency distribution, with the highest apoptotic yield at the crypt base. The caecal colon has a pattern of apoptotic distribution more similar to that in the small intestine. After exposure to 1 Gy ionizing radiation, the maximum apoptotic yield occurs over a period of 3-6 h in the small intestine. There is some unexplained variability in the values between groups of mice and between different mouse strains. After 8 Gy, the yield remains elevated for several days, however a similar maximum yield is still observed at the early times. In mouse large intestine and rat small intestine, the yield continues to rise until about 6 Gy in mouse large intestine and until at least 10 Gy in rat small intestine. Spontaneous apoptosis is interpreted as part of the homeostatic mechanism regulating stem cell numbers. About 1.6 cells per crypt are dying at any one time. Following irradiation, there is an apparent relationship between mitotic and apoptotic levels, suggesting that these processes are linked. The dose-response relationship suggests that there are about six apoptosis-susceptible cells in crypts of the small intestine, with about 2-4 of these occurring at cell positions in which there are other more resistant clonogenic cells. In the large intestine, the position of these apoptosis-susceptible cells varies with region, but the numbers are similar.
CitationThe relationship between ionizing radiation-induced apoptosis and stem cells in the small and large intestine. 1998, 78 (8):993-1003 Br. J. Cancer
JournalBritish Journal of Cancer
- Radiation-induced mitotic delay: duration, dose and cell position dependence in the crypts of the small intestine in the mouse.
- Authors: Chwalinski S, Potten CS
- Issue date: 1986 May
- The re-establishment of hypersensitive cells in the crypts of irradiated mouse intestine.
- Authors: Ijiri K, Potten CS
- Issue date: 1984 Nov
- Differential survival of murine small and large intestinal crypts following ionizing radiation.
- Authors: Cai WB, Roberts SA, Bowley E, Hendry JH, Potten CS
- Issue date: 1997 Feb
- Radiation-induced p53 and p21WAF-1/CIP1 expression in the murine intestinal epithelium: apoptosis and cell cycle arrest.
- Authors: Wilson JW, Pritchard DM, Hickman JA, Potten CS
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- Cell migration in the small and large bowel shows a strong circadian rhythm.
- Authors: Qiu JM, Roberts SA, Potten CS
- Issue date: 1994