Regeneration in small intestine following exposure to X-radiation and neutron beam as estimated in the light of changes in alkaline phosphatase activity and degree of 3H-thymidine incorporation into cells in intestinal crypts.

Swiss mice were irradiated with X-rays (5, 7 and 9 Gy) and neutrons (3 and 5 Gy) determining the degree of 3H-thymidine incorporation into the cells in the intestinal crypts, alkaline phosphatase activity in intestinal homogenate and serum, and radiation-induced leucopenia. It was shown that damage to the cells in intestinal crypts depends on the dose and type of radiation. More radiation-resistant cells covering the intestinal villi showed a significant inhibition of alkaline phosphatase activity at high radiation doses. Changes in intestinal alkaline phosphatase activity were reflected also by changes in its level in the serum where its dependence on the dose of radiation was evident also.