Evaluation of a role for intracellular Na+, K+, Ca2+, and Mg2+ in hyperthermic cell killing.
A dose of heat which renders 98% of a population of Chinese hamster ovary cells reproductively dead has no significant effect on their Na+, K+, or Mg2+ content by 28 h postheat. In contrast, the cellular Ca2+ content increases in a dose-dependent manner as observed at 22 h after heating for 15-35 min at 45 degrees C. However, the rates of both influx and efflux of Ca2+ were reduced by heating. Increasing the cellular Ca2+ content by incubating the cells in high extracellular Ca2+, either at the time of heating or for a period of 22 h following heat, does not potentiate the lethal effect of heat. Completely blocking the heat-induced increase in Ca2+ content by incubating the cells in medium containing a low Ca2+ concentration does not protect the cells. Therefore, we conclude that heat does not produce any significant changes in the Na+, K+, or Mg2+ content of cells and that the heat-induced increase in Ca2+ does not play an important role in hyperthermic cell killing.
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival; D006224:Cricetinae; D003412:Cricetulus; D006358:Hot Temperature; D066298:In Vitro Techniques; D008274:Magnesium / Q000502:physiology*; D011188:Potassium / Q000502:physiology*; D012964:Sodium / Q000502:physiology; D013997:Time Factors
D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium