DDOSE-EFFECT RELATIONSHIPS IN MOUSE SMALL INTESTINE IRRADIATED WITH HIGH DOSES OF γ-RAYS

Three strains of male albino mice were total-bodily irradiated with 10-100 Gy of ~(50)Co γ-rays. They were sacriticed 72 hours post irradiation, and their whole small intestines were removed to obtain the following four measurements: intestinal length, intestinal area, intestinal dry weight and number of intestinal crypts in a longitudinal histological section of whole small intestine.The dose-effect curves were fitted with these measurements. They are biphasic curves: a steep part, below the saturation dose (about 20 Gy), and a more or less flat part, above that dose.The technique of direct counting of the numbers of crypts in the longitudinal histological sections of the whole murine small intestine has not been reported in the literature. There is no information on changes in intestinal area induced by ionizing radiation either. However, these two measurements are rather sensitive to ionizing radiation. They can be easily and precisely measured.