Effect of Pseudomonas contamination or antibiotic decontamination of the GI tract on acute radiation lethality after neutron or gamma irradiation

Journal Article · Sun Dec 01 04:00:00 EST 1985 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576599· OSTI ID:5685350

Geraci, J P; Jackson, K L; Mariano, M S

The influence of antibiotic decontamination of Pseudomonas contamination of the GI tract prior to whole-body neutron or gamma irradiation was studied. It was observed that for fission neutron doses greater than 5.5 Gy, cyclotron-produced neutron doses greater than 6.7 Gy, and 137Cs gamma-ray doses greater than 14.4 Gy, the median survival time of untreated rats was relatively constant at 4.2 to 4.5 days, indicating death was due to intestinal injury. Within the dose range of 3.5 to 5.5 Gy of fission neutrons, 4.9 to 6.7 Gy of cyclotron-produced neutrons, and 9.6 to 14.4 Gy of gamma rays, median survival time of these animals was inversely related to dose and varied from 12 to 4.6 days. This change in survival time with dose reflects a transition in the mechanisms of acute radiation death from pure hematopoietic, to a combination of intestinal and hematopoietic, to pure intestinal death. Decontamination of the GI tract with antibiotics prior to irradiation increased median survival time 1 to 5 days in this transitional dose range. Contamination of the intestinal flora with Pseudomonas aeruginosa prior to irradiation reduced median survival time 1 to 5 days in the same radiation dose range. Pseudomonas-contaminated animals irradiated within this transitional dose range had maximum concentrations of total bacteria and Pseudomonas in their livers at the time of death. However, liver bacteria concentration was usually higher in gamma-irradiated animals, due to a smaller contribution of hematopoietic injury in neutron-irradiated animals. The effects of both decontamination of the GI tract and Pseudomonas contamination of the GI tract were negligible in the range of doses in which median survival time was dose independent, i.e., in the pure intestinal death dose range.

• Research Organization: Univ. of Washington, Seattle
• OSTI ID: 5685350
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACUTE EXPOSURE
ANIMALS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BACTERIA
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DIGESTIVE SYSTEM
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EXTERNAL IRRADIATION
FERMIONS
GAMMA RADIATION
GASTROINTESTINAL TRACT
HADRONS
INFECTIVITY
IONIZING RADIATIONS
IRRADIATION
LETHAL IRRADIATION
MAMMALS
MICROORGANISMS
NEUTRONS
NUCLEONS
PSEUDOMONAS
RADIATION EFFECTS
RADIATIONS
RATS
RESPONSE MODIFYING FACTORS
RODENTS
STERILIZATION
SURVIVAL TIME
VERTEBRATES
WHOLE-BODY IRRADIATION