[Ultrastructure of the vessels of the submucosal membrane of the rat small intestine at long intervals following fractionated irradiation].

The time course of ultrastructural changes in the walls of arterial type vessels was studied in the small intestinal submucous membrane of Wistar male rats long after fractionated irradiation of the abdominal area. Three phases were identified in the development of vascular response to irradiation; mechanisms of their development are under discussion.