RÉSUMÉ
One hundred and forty mice, weighing 30-35 grams, were divided into irradiation group (12 Gy total body irradiation from a 60Co source), combined radiation-burn group (12 Gy total body irradiation and 15% TBSA third degree burns), and normal control group.The dynamic changes of the intestinal epithelium were observed with light and electron microscopes and autoradiography within 96 hours after injuries, and attention was paid to the formation and conversion of the misshapen cells. It was Jound that the proliferative cycle of the young cells in the intestinal crypts which were severely injuried by irradiation was significantly retarded, and their G1-phase to G2-phase were prolonged. These cells gradually changed into misshapen cells. Some of the misshapen cells could not divide and finally they wer.e desquamated; abortive proliferation was found in some of them; some others showed pathological karyokinesis. Thus polymorphic cells were formed. It was difficult to show that the misshapen cells could take part in the repair of the intestinal epithelium. It is speculated that the misshapen cells might to some extent have the function of absorption, secretion and barrier.