Accession Number : ADA268336


Title :   Survival After Total Body Irradiation: Effects of Irradiation of Exteriorized Small Intestine


Corporate Author : ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD


Personal Author(s) : Vriesendorp, H M ; Vigneulle, R M ; Kitto, G ; Pelky, T ; Taylor, P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a268336.pdf


Report Date : Jan 1993


Pagination or Media Count : 11


Abstract : Rats receiving lethal irradiation to their exteriorized small intestine with pulsed 18 MVp bremsstrahlung radiation live about 4 days longer than rats receiving a dose of total-body irradiation (TBI) causing intestinal death. The LD50 for intestinal irradiation is approximately 6 Gy higher than the LD50 for intestinal death after TBI. Survival time after exteriorized intestinal irradiation can be decreased, by adding abdominal irradiation. Adding thoracic or pelvic irradiation does not alter survival time. Shielding of large intestine improves survival after irradiation of the rest of the abdomen while the small intestine is also shielded. The kinetics of histological changes in small intestinal tissues implicate the release of humoral factors after irradiation of the abdomen. Radiation injury develops faster in the first (proximal) 40 cm of the small intestine and is expressed predominantly as shortening in villus height. In the last (distal) 40 cm of the small intestine, the most pronounced radiation effect is a decrease in the number of crypts per millimeter. Irradiation (20 Gy) of the proximal small intestine causes 92 % mortality (median survival 10 days). Irradiation (20 Gy) of the distal small intestine causes 27% mortality (median survival 30 days). In addition to depletion of crypt stem cells in the small intestine, other issues (humoral factors, irradiated subsection of the small intestine and shielding of the large intestine) appear to influence radiation-induced intestinal mortality.


Descriptors :   *IRRADIATION , *BODIES , *RADIATION DOSAGE , *SMALL INTESTINE , DEPLETION , REPRINTS , TISSUES(BIOLOGY) , RATS , CELLS , TIME , SURVIVAL(PERSONNEL) , MORTALITY RATE , ADDITION , RADIATION INJURIES , BIOPSY , REST , RADIATION EFFECTS , ABDOMEN , INTESTINES , LETHAL DOSAGE , HEIGHT , BREMSSTRAHLUNG , DEATH , NUMBERS , RELEASE , SHIELDING , WOUNDS AND INJURIES , LETHALITY , KINETICS


Subject Categories : Anatomy and Physiology
      Radiobiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE