Shen G L
Radiobiology Laboratory, Henan Tumor Institute, Zhengzhou.
Zhonghua Zhong Liu Za Zhi. 1989 Mar;11(2):89-91.
The thermotolerant kinetics of HEp-2 cells and its effect on cytotoxicity of Nitrocaphane (NC) were studied by colony formation assay. HEp-2 cells were exposed to two equal thermal doses (44 degrees C, 30 min) spaced at 0-24 hr intervals during which the cells were incubated at 37 degrees C. The maximum thermotolerance developed at the 8th hr and then gradually declined. Thermal dose survival curve even up to 2.5 hr of continuous exposure to 44 degrees C, no development of thermotolerance was demonstrated. If the cells were preheated at 44 degrees C for 30 min, and returned to 37 degrees C for 10 hr and then received the second heating at 44 degrees C for 3 hr, the slope of survival curve decreased (D0 = 2.26 hr). Thermotolerant ratio was 5.9. Thermosensitive HEp-2 cells were turned into thermotolerant cells by preheating at 44 degrees C, 30 min and returning to 37 degrees C for 10 hr. The thermotolerant cells showed resistance to drug or heat when they were exposed to NC or NC combined with heat.
采用集落形成试验研究了人喉表皮样癌细胞（HEp-2细胞）的耐热动力学及其对卡莫司汀（NC）细胞毒性的影响。将HEp-2细胞暴露于两个相等的热剂量（44℃，30分钟），间隔0 - 24小时，在此期间细胞于37℃孵育。在第8小时形成最大耐热性，然后逐渐下降。即使连续暴露于44℃长达2.5小时，热剂量存活曲线也未显示出耐热性的形成。如果细胞先在44℃预热30分钟，然后回到37℃孵育10小时，接着再接受44℃的第二次加热3小时，存活曲线的斜率降低（D0 = 2.26小时）。耐热比为5.9。通过在44℃预热30分钟并回到37℃孵育10小时，可将热敏性HEp-2细胞转变为耐热细胞。当耐热细胞暴露于NC或NC与热联合作用时，表现出对药物或热的抗性。
