Antibiotic radioprotection of mice exposed to supralethal whole-body irradiation independent of antibacterial activity. [Gamma radiation, streptomycin, kanamycin, neomycin, gentamycin]
Oral administration of streptomycin, kanamycin, neomycin, or gentamicin to specific pathogen-free C57 x Af mice in their drinking water (4 mg/ml) for 2 weeks before supralethal whole-body irradiation very significantly prolonged their mean survival times (8.2 to 8.9 days vs 6.9 for controls) to values which exceed those reported for germ-free mice (7.3 days). The total fecal concentrations of aerobes and anaerobes were reduced by kanamycin, neomycin, and gentamicin. Streptomycin reduced the anaerobes significantly, but not the aerobes. Unlike germ-free mice, these antibiotic-treated mice did excrete free bile acids, products of bacterial action. Oral antibiotic treatment was ineffective in altering the transit time of the intestinal mucosal cells. Previously reported studies had indicated a correlation between decreased transit time and increased survival after irradiation. No significant correlation between mean survival time after irradiation and mucosal transit time was observed. The data demonstrate that certain antibiotics alter the character of the intestinal bacterial flora and increase protection against supralethal doses of whole-body irradiation. It is concluded that the mechanisms of radioresistance in antibiotic-treated mice and germ-free mice are different and that in both groups radioresistance is the result of more than elimination of postirradiation infection.
- Research Organization:
- Baylor Coll., Houston, TX
- OSTI ID:
- 7238548
- Journal Information:
- Radiat. Res.; (United States), Vol. 68:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANTIBIOTICS
RADIOSENSITIVITY EFFECTS
BACTERIA
BIOLOGICAL RADIATION EFFECTS
GAMMA RADIATION
INTESTINES
MICE
RADIATION PROTECTION
STREPTOMYCIN
SURVIVAL TIME
WHOLE-BODY IRRADIATION
ANIMALS
BIOLOGICAL EFFECTS
BODY
DIGESTIVE SYSTEM
DRUGS
ELECTROMAGNETIC RADIATION
EXTERNAL IRRADIATION
GASTROINTESTINAL TRACT
IONIZING RADIATIONS
IRRADIATION
MAMMALS
MICROORGANISMS
ORGANS
RADIATION EFFECTS
RADIATIONS
RODENTS
VERTEBRATES
560152* - Radiation Effects on Animals- Animals