LATE EFFECT IN MOUSE SKIN FOLLOWING SINGLE AND MULTIFRACTIONATED IRRADIATION

Abstract The time course of mouse skin contraction after single-dose and multifractionated gamma-irradiation using various time intervals was studied until day 540 after irradiation. Following an initial shrinkage of the skin, a period of relaxation was observed 20 to 30 days after irradiation. Thereafter there was a dose dependent period before a second wave of contraction began, which was earlier and more severe with increasing dose. Recovery from sub-effective injury, as measured by increase in dose for an isoeffect, was not complete within 12 hours. Constant exponents for N and T in an isoeffect formula are not appropriate for the data presented.