Temperature-dependence of ATP level, organic phosphate production and Na,K-ATPase in human lymphocytes.

It was previously shown that human lymphocytes maintain a normal accumulation of K+ and exclusion of Na+ between 37 degrees and 10 degrees C., and a significant net accumulation of K+ and exclusion of Na+ at even lower temperatures. The studies reported here show that the level of ATP is near-normal for at least 24 hours between 37 degrees and 10 degrees C., but that ATP synthesis and utilization are progressively and markedly decreased with decreasing temperatures below 37 degrees C. The activities of the membrane Na+- and K+-activated ATPases have typical marked temperature-dependences. Therefore, the normal accumulation of K+ and exclusion of Na+ between 37 degrees and 10 degrees C., and the normal rate of Na+ efflux at these temperatures, do not correlate with properties of the Na+,K+-ATPase or with rates of synthesis and utilization of ATP.