Increased intestinal mucosal turnover and radiosensitivity to supralethal whole-body irradiation resulting from cholic acid-induced alterations of the intestinal microecology of germfree CFW mice. [X radiation]
The prolonged mean survival time of germfree mice, compared to conventional mice, after exposure to 1000-10,000 rad whole-body irradiation has been postulated to be a function of an increased turnover time of the intestinal mucosal cells caused by the absence of free bile acids. To test this hypothesis, the diet of germ-free CFW mice was supplemented with 0.15 percent cholic acid for 2 weeks. The turnover of thymidine-labeled intestinal mucosal cells and the radiosensitivity to supralethal whole-body irradiation were significantly increased compared to germfree controls. There was a positive correlation between increased survivial time after supralethal whole-body irradiation and slower intestinal mucosal turnover time. Germfree mice supplemented with cholic acid had intestinal mucosal turnover times comparable to those of conventionalized controls. Although cholic acid reduces the mean survival time of germfree mice after suppralethal whole-body irradiation, the mean survival value is significantly greater than the conventionalized controls. Supplementing the diet of conventionalized CFW mice with cholic acid did not significantly decrease the intestinal mucosal turnover time nor did it significantly alter their radiosensitivity to supralethal whole-body irradiation. The data suggest that cholic acid is one of the microecological factors responsible for controlling the mucosal renewal rate and the mean survival time after whole-body irradiation.
- Research Organization:
- Baylor Coll. of Medicine, Houston, TX
- OSTI ID:
- 7275963
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 66:2; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BILE ACIDS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
CARBOXYLIC ACIDS
CELL PROLIFERATION
CHOLIC ACID
DIET
DIGESTIVE SYSTEM
ELECTROMAGNETIC RADIATION
EXTERNAL IRRADIATION
GASTROINTESTINAL TRACT
GERM-FREE ANIMALS
HYDROXY COMPOUNDS
INTESTINES
IONIZING RADIATIONS
IRRADIATION
MAMMALS
MICE
MUCOUS MEMBRANES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RODENTS
STEROIDS
STEROLS
SURVIVAL TIME
VERTEBRATES
WHOLE-BODY IRRADIATION
X RADIATION