Previous work showed that intracellular pH ( pH i) and not extracellular pH ( pH e) was the determinant in the low pH sensitization of hyperthermic killing. The present studies show that the same is true for heat-induced radiosensitization and loss of cellular DNA polymerase activities. Chinese hamster ovary cells after they had adapted to low pH (6.7) had an increase in pH i which rendered cells partially resistant to the low pH sensitization of heat-induced cell killing, radiosensitization, and loss of cellular DNA polymerase activities. These results were quantified by plotting versus pH e, both the thermal enhancement ratio (TER), defined as the ratio of the X-ray dose without heat to the X-ray dose with heat to give an isosurvival value of 0.01, and the thermal enhancement factor (TEF), defined as the ratio of the D0 of the radiation survival curve to the D0 of the radiation survival curve for heat plus radiation. Both the TER and TEF were higher for the unadapted cells than for the adapted cells, i.e., 1.3-1.4 fold higher at a pH e of 6.3. However, the TER or TEF plotted versus pH i was identical for the two cell types. Finally, heat-induced loss of cellular DNA polymerase activities correlated with pH i and not pH e. Therefore, we conclude that pH i and not pH e is responsible for the increase by acid in heat-induced radiosensitization and loss of cellular DNA polymerase activities.
Skip Nav Destination
Research Article| September 01 1988
The Role of Low Intracellular or Extracellular pH in Sensitization to Hyperthermic Radiosensitization
Radiat Res (1988) 115 (3): 576–585.
- Views Icon Views
- Share Icon Share
- Search Site
Guo L. Chu, William C. Dewey; The Role of Low Intracellular or Extracellular pH in Sensitization to Hyperthermic Radiosensitization. Radiat Res 1 September 1988; 115 (3): 576–585. doi: https://doi.org/10.2307/3577306
Download citation file:
Citing articles via
Commonalities Between COVID-19 and Radiation Injury
Carmen I. Rios, David R. Cassatt, Brynn A. Hollingsworth, Merriline M. Satyamitra, Yeabsera S. Tadesse, Lanyn P. Taliaferro, Thomas A. Winters, Andrea L. DiCarlo
Low-Dose Radiation Therapy (LDRT) for COVID-19: Benefits or Risks?
Pataje G. Prasanna, Gayle E. Woloschak, Andrea L. DiCarlo, Jeffrey C. Buchsbaum, Dörthe Schaue, Arnab Chakravarti, Francis A. Cucinotta, Silvia C. Formenti, Chandan Guha, Dale J. Hu, Mohammad K. Khan, David G. Kirsch, Sunil Krishnan, Wolfgang W. Leitner, Brian Marples, William McBride, Minesh P. Mehta, Shahin Rafii, Elad Sharon, Julie M. Sullivan, Ralph R. Weichselbaum, Mansoor M. Ahmed, Bhadrasain Vikram, C. Norman Coleman, Kathryn D. Held
Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light
Manuela Buonanno, Brian Ponnaiya, David Welch, Milda Stanislauskas, Gerhard Randers-Pehrson, Lubomir Smilenov, Franklin D. Lowy, David M. Owens, David J. Brenner