Effect of pH and cell cycle progression on development and decay of thermotolerance.
Synchronous Chinese hamster ovary cells were heated in G1 and incubated at 37 degrees C at pH 6.75 or pH 7.4 before they were heated a second time. The magnitude and rate of development and decay of thermotolerance were greatly reduced at pH 6.75. This was also observed for asynchronous cells. Furthermore, the heat-induced delay in cell cycle progression was greatly enhanced at low pH and correlated with the reduced rate for development and decay of thermotolerance. However, studies with [3H]TdR to kill cells entering S phase showed that the decay of thermotolerance is relatively independent of the cell cycle. Therefore, low pH apparently slows many cell processes, including those associated with heat-induced cell cycle delay and the rate of development and decay of thermotolerance.
D000818:Animals; D002453:Cell Cycle; D002470:Cell Survival; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007399:Interphase; D051379:Mice; D008938:Mitosis; D013997:Time Factors