Lee Y J, Perlaky L, Dewey W C, Armour E P, Corry P M
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan 48072.
Radiat Res. 1990 Mar;121(3):295-303.
Chinese hamster ovary (CHO) cells became thermotolerant after treatment with either heat for 10 min at 45.5 degrees C or incubation in 100 microM sodium arsenite for 1 h at 37 degrees C. Thermotolerance was tested using heat treatment at 45 degrees C or 43 degrees C administered 6-12 h after the inducing agent. At 45 degrees C thermotolerance ratios at 10(-2) isosurvival levels were 4.2 and 3.8 for heat and sodium arsenite, respectively. Recovery from heat damage as measured by resumption of protein synthesis was more rapid in heat-induced thermotolerant cells than in either sodium arsenite-induced thermotolerant cells or nonthermotolerant cells. Differences in inhibition of protein synthesis between heat-induced thermotolerant cells and sodium arsenite-induced thermotolerant cells were also evident after test heating at 43 degrees C for 5 h. At this temperature heat-induced thermotolerant cells were protected immediately from inhibition of protein synthesis, whereas sodium arsenite-induced thermotolerant cells, while initially suppressed, gradually recovered within 24 h. Furthermore, adding cycloheximide during the thermotolerance development period greatly inhibited sodium arsenite-induced thermotolerance (SF less than 10(-6] but not heat-induced thermotolerance (SF = 1.7 X 10(-1] when tested with 43 degrees C for 5 h. Our results suggest that both the development of thermotolerance and the thermotolerant state for the two agents, while similar in terms of survival, differed significantly for several parameters associated with protein synthesis.
中国仓鼠卵巢（CHO）细胞在45.5℃下加热10分钟或在37℃下于100μM亚砷酸钠中孵育1小时后会产生耐热性。在诱导剂处理6 - 12小时后，通过在45℃或43℃下进行热处理来测试耐热性。在45℃时，对于加热和亚砷酸钠处理，10^(-2)等存活水平下的耐热比分别为4.2和3.8。与亚砷酸钠诱导的耐热细胞或非耐热细胞相比，热诱导的耐热细胞中通过蛋白质合成恢复来衡量的热损伤恢复更快。在43℃下测试加热5小时后，热诱导的耐热细胞和亚砷酸钠诱导的耐热细胞之间蛋白质合成抑制的差异也很明显。在此温度下，热诱导的耐热细胞立即受到保护，免受蛋白质合成抑制，而亚砷酸钠诱导的耐热细胞虽然最初受到抑制，但在24小时内逐渐恢复。此外，在耐热性发展期间添加环己酰亚胺极大地抑制了亚砷酸钠诱导的耐热性（SF小于10^(-6)），但对热诱导的耐热性没有影响（当在43℃下测试5小时时，SF = 1.7×10^(-1)）。我们的结果表明，两种试剂的耐热性发展和耐热状态，虽然在存活方面相似，但在与蛋白质合成相关的几个参数上有显著差异。
