Hartson-Eaton M, Malcolm A W, Hahn G M
Radiat Res. 1984 Jul;99(1):175-84.
CHO cells subline HA-1 were made thermotolerant by a priming heat treatment (43 degrees C, 30 min). Later, 4, 16, or 24 hr, they were either irradiated or heated (43 degrees C, 30 min) and irradiated. Thermotolerance had no effect on the radiation sensitivity of the cells as measured by the D0 value of the clonogenic survival curve. However, the N value of the curve (width of shoulder) showed a significant increase at 24 hr, indicating an increased capacity to accumulate sublethal damage. This indicates that the fractionation schedule 43 degrees C, 30 min + 37 degrees C, 24 hr + 43 degrees C, 30 min + X ray required approximately 100 rad more radiation than 43 degrees C, 30 min + X ray to reduce survival to the same level. The same priming treatment was given to RIF-1 tumors growing in C3H mice. Later, 24 hr, when the tumors were either irradiated or heated (43 degrees C, 30 min) and irradiated, it was found that thermotolerance had no effect on the radiosensitivity of the cells as measured by in vitro assay. However, thermal radiosensitization was not apparent 24 hr after the priming treatment.
通过预适应热处理（43℃，30分钟）使CHO细胞亚系HA-1产生耐热性。随后，在4、16或24小时后，对其进行照射或加热（43℃，30分钟）并照射。如通过克隆存活曲线的D0值所测，耐热性对细胞的辐射敏感性没有影响。然而，曲线的N值（肩部宽度）在24小时时显著增加，表明积累亚致死损伤的能力增强。这表明，与43℃，30分钟 + X射线相比，43℃，30分钟 + 37℃，24小时 + 43℃，30分钟 + X射线的分次照射方案需要多约100拉德的辐射才能将存活率降低到相同水平。对在C3H小鼠体内生长的RIF-1肿瘤给予相同的预适应处理。随后，在24小时时，当肿瘤接受照射或加热（43℃，30分钟）并照射时，发现如通过体外测定所测，耐热性对细胞的放射敏感性没有影响。然而，在预适应处理24小时后，热放射增敏并不明显。
