Wondergem J, Haveman J
Int J Radiat Biol Relat Stud Phys Chem Med. 1985 Sep;48(3):337-48. doi: 10.1080/09553008514551341.
We studied the reaction of the mouse foot after combined X-irradiation and heat treatment. Acute reactions after heat differ from those after irradiation, however, after healing of the lesions, the same symptoms of deformity of the mouse foot remain. Prior heat treatment, 30 min at 43 degrees C, of the foot led to thermotolerance and this thermotolerance resulted in resistance to combined irradiation-heat treatments and hence to a decreased thermal enhancement of radiation effects. Resistance could be observed up to 168 h after prior heat treatment. The development of resistance to combined treatment at higher irradiation dose (15 or 20 Gy) and less severe heating was slower than at lower irradiation dose (10 Gy) and more severe heating. Thermal enhancement was confirmed to be dependent on the sequence of, and the interval between irradiation and heat treatment. When the mouse foot was made thermotolerant by prior heat treatment, thermal enhancement was always reduced, regardless of the sequence, when the combined heat and radiation treatments were given with an interval of less than 12 h. Thermotolerance led to an apparent decrease in the effective temperature employed in a combined treatment equivalent to approximately 1.0 degrees C, at temperatures above 43 degrees C in a 1 h heat treatment.
我们研究了小鼠足部在联合X射线照射和热处理后的反应。热疗后的急性反应与辐射后的不同，然而，在损伤愈合后，小鼠足部相同的畸形症状依然存在。对足部进行43摄氏度、30分钟的预先热处理可导致热耐受，这种热耐受会产生对联合照射-热疗的抗性，从而降低辐射效应的热增强作用。在预先热处理后长达168小时都能观察到抗性。在较高照射剂量（15或20 Gy）和不太严重加热条件下，对联合治疗抗性的发展比对较低照射剂量（10 Gy）和更严重加热条件下要慢。热增强作用被证实取决于照射和热处理的顺序以及二者之间的间隔。当通过预先热处理使小鼠足部产生热耐受时，若联合热疗和辐射治疗的间隔小于12小时，无论顺序如何，热增强作用总是会降低。在1小时热处理且温度高于43摄氏度的情况下，热耐受导致联合治疗中使用的有效温度明显降低约1.0摄氏度。
