skip to main content

Title: Survival after total-body irradiation. I. Effects of partial small bowel shielding

The small intestine of the rat was shielded during total-body irradiation (TBI) to evaluate the effects of radiation dose and length of intestine shielded on survival. Sprague-Dawley rats were anesthetized in groups of 10. Using aseptic surgical procedures 80, 40, 20, or 10 cm, or none of the proximal or distal small intestine were temporarily exteriorized and shielded during irradiation with photons from an 18 MeV linear accelerator. Less than 17% of the dose was delivered to the shielded intestines. In unshielded animals deaths occurred from Days 4 to 6 with 13, 15, or 17 Gy and from Days 8 to 30 with 9, 11, and 12 Gy. However, in all animals exposed to 15 Gy with all or part of the small intestine shielded, survival was increased to between 5 and 9 days. Shielding of the distal small intestine was more effective in prolonging survival than shielding of the proximal small intestine. The previously identified target of radiation damage in the small intestine is the crypt stem cell. In this study, the analysis of histological specimens of shielded and irradiated small intestine suggested that humoral factors also influence intestinal histology and survival after irradiation. These humoral factors are thoughtmore » to originate from the irradiated body tissues, the shielded proximal intestine, and the shielded distal intestine. Further studies are required to identify these factors and to determine their mode of action and their therapeutic potential after radiation damage to the small intestine.« less
Authors:
; ; ; ;  [1]
  1. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))
Publication Date:
OSTI Identifier:
5669006
Resource Type:
Journal Article
Resource Relation:
Journal Name: Radiation Research; (USA); Journal Volume: 119:2
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; SMALL INTESTINE; RADIATION PROTECTION; BIOLOGICAL RADIATION EFFECTS; BIOLOGICAL SHIELDING; PHOTONS; RADIATION DOSES; RADIATION INJURIES; RATS; SURVIVAL CURVES; WHOLE-BODY IRRADIATION; ANIMALS; BIOLOGICAL EFFECTS; BODY; DIGESTIVE SYSTEM; DOSES; ELEMENTARY PARTICLES; EXTERNAL IRRADIATION; GASTROINTESTINAL TRACT; INJURIES; INTESTINES; IRRADIATION; MAMMALS; MASSLESS PARTICLES; ORGANS; RADIATION EFFECTS; RODENTS; SHIELDING; VERTEBRATES 560152* -- Radiation Effects on Animals-- Animals