Lee Y J, Dewey W C
Radiat Res. 1986 Apr;106(1):98-110.
Cycloheximide (CHM) and puromycin (PUR) were used at various concentrations up to maxima of 10 micrograms/ml and 100 micrograms/ml, respectively, which inhibited protein synthesis by 95% without any cytotoxicity. The drugs were added to the cells for a maximum period of 7 h, with various combinations for treatment before, during, and after heating. Maximum protection, i.e., a 10,000-fold increase in survival from 5 X 10(-6) to 5 X 10(-2) after 4 h at 43 degrees C, required both 1-2 h of treatment before heating and 1-2 h of treatment during heating. For treatments at 45.5 degrees C, the protection was less, i.e., a 100-fold increase in survival from 10(-5) to 10(-3). Little or no protection was observed if after treatment, the drug was removed before heating, or if the drug was added at the start of heating and left on for 5 min to 3 h after heating. For both drugs, the amount of protection increased as inhibition of protein synthesis increased. However, the amount of protection from the drugs was the same only at about 95% inhibition; at 60-85% inhibition, CHM afforded more protection than PUR. Therefore, the modes of action of the drugs might be common at high drug concentrations, but different when intermediate concentrations are used.
放线菌酮（CHM）和嘌呤霉素（PUR）分别以高达10微克/毫升和100微克/毫升的不同浓度使用，它们可抑制蛋白质合成达95%，且无任何细胞毒性。将药物添加到细胞中的最长时间为7小时，在加热前、加热期间和加热后采用不同的组合进行处理。最大程度的保护，即在43℃处理4小时后存活率从5×10⁻⁶提高到5×10⁻²，提高了10000倍，这需要在加热前处理1 - 2小时以及在加热期间处理1 - 2小时。对于45.5℃的处理，保护作用较小，即存活率从10⁻⁵提高到10⁻³，提高了100倍。如果在处理后加热前去除药物，或者在加热开始时添加药物并在加热后持续作用5分钟至3小时，则几乎观察不到保护作用。对于这两种药物，保护程度随着蛋白质合成抑制作用的增强而增加。然而，只有在约95%的抑制率时，两种药物的保护程度才相同；在60 - 85%的抑制率时，放线菌酮提供的保护比嘌呤霉素更多。因此，这两种药物的作用方式在高药物浓度时可能相同，但在使用中等浓度时则不同。
