Some Characteristics of the Survival Curve of Crypt Cells of the Small Intestine of the Mouse deduced after Whole Body X Irradiation

Abstract

The dose required to kill mice three to four days after whole body X-irradiation is compared after single and after fractionated doses. It is assumed that death at three to four days after irradiation is due to the reduction of the crypt cells of the small intestine to a constant, though unknown, survival level. The difference in the dose required to produce this effect after single or fractionated doses gives a measure of the size of the shoulder on a “Type C” survival curve. The results suggest that the shoulder of the survival curve for the crypt cells of Leiberkühn is large, with DQ more than 400 r and n more than 28.