Alternative types of duodenal ulcer induced in mice by partial X irradiation of the thorax.

The present study extends our earlier observations [A. Michalowski, Br. J. Radiol. 54, 713 (1981); A. Michalowski and J. Burgin, in Progress in Radio-Oncology II, pp. 105-110] on gastrointestinal pathology in thorax-irradiated female CFLP mice. It shows that exposure of the lower mediastinum to single doses of 14-30 Gy X rays results in the formation of the proximal duodenal ulcer accompanied frequently by erosion of the antral gastric mucosa. X irradiation of the lateral thoracic fields is responsible for single ulcers in the proximity of duodenal papilla, often associated with a circumscribed area of degeneration of the fundic mucosa of the stomach. In view of the small amount of radiation received by the subdiaphragmatic parts of the alimentary tract, these gastro-duodenal lesions represent abscopal effects of thoracic irradiation.