Experimental Therapy of the Gastrointestinal Syndrome Produced by Lethal Doses of Ionizing Radiation

Abstract
The gastrointestinal syndrome and its therapy were studied in dogs, one control group of eight dogs receiving 1300–1500 r of Co60 gamma radiation and another group of eight dogs, 1800 r of 2 mev roentgen radiation. The dogs developed acute gastrointestinal symptoms of anorexia, nausea, vomiting and copious diarrhea (often sanguineous). Death occurred in all these dogs on the 3rd or 4th days after irradiation, associated with fluid and electrolyte loss with acute dehydration and vascular collapse. Experimental therapy was carried out in a group of 11 dogs receiving the same dose of gamma radiation using parenteral infusions of balanced electrolyte solutions, plasma, protein hydrolysates, antibiotics and vitamin supplements. Dogs responded dramatically. The survival times were increased in many dogs into the 2nd week when death occurred, presumably associated with the effects of pancytopenia. Gross and microscopic studies on dogs killed in the moribund state on the 3rd and 4th days showed marked congestion of the serosa and mucosal ridges, particularly of the small intestine, with sanguineous fluid in the peritoneal cavity and in the intestines of some dogs. Microscopically the villi of the mucosa were flattened with areas denuded of epithelium. In the treated dogs living into the 2nd week, congestion was much less pronounced, and complete, or nearly complete, regeneration of the mucosa was noted. The rigorous therapeutic regimen was undoubtedly responsible for extending the lives of the irradiated dogs beyond the period of mortality associated with the gastrointestinal syndrome. Submitted on March 21, 1956