Lack of thermal inhibition of radiation damage repair in the late-appearing foot reaction.
Our previous study on early- and late-appearing murine foot reactions following combined hyperthermia and irradiation suggested that hyperthermia may not inhibit repair of sublethal and/or potentially lethal radiation damage for the late-appearing reaction. A series of split dose experiments was performed by using C3Hf/Sed mouse foot reaction, which showed both early and late responses in the same tissue. Hyperthermia given in a 43.5 degrees C water bath for 45 min inhibited radiation damage repair in the early-appearing reaction, but was not able to modify repair in the late-appearing reaction. The failure of thermal inhibition of radiation damage repair in the late-appearing reaction was observed regardless of the sequence of heat and irradiation. Complete repair appeared to require approximately 9 hr. Although it is unknown whether radiation damage repair can be completely inhibited in all late-responding normal tissues, the reduction in thermal repair inhibition in some late-responding tissues may be an advantage of "heat prior to irradiation" treatment over radiation alone.
Urano
M
M
Department of Radiation Medicine, University of Kentucky Medical Center, Lexington 40536.
D000818:Animals; D002588:Cesium Radioisotopes; D004260:DNA Repair; D005528:Foot / Q000528:radiation effects*; D006358:Hot Temperature; D051379:Mice; D008809:Mice, Inbred C3H; D011833:Radiation Injuries, Experimental / Q000235:genetics / Q000517:prevention & control*; D013997:Time Factors
D002588:Cesium Radioisotopes