Re-irradiation of mouse skin: similarity of dose reductions for healing and macrocolony endpoints.

Abstract

The amount of residual injury in mouse tail skin, assessed by the decrease in re-irradiation dose for equal effect, was similar whether assessed using healing or colony endpoints (17-21% after single priming doses). There were tendencies towards an increased sensitivity of the colony-forming cells by a factor of about 2, and less residual injury after multifractionated priming doses. These observations are compatible with a lower alpha/beta ratio characterising the response to dose fractionation for residual injury than for the acute healing response.