Experimental hematology
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Experimental hematology · Oct 1991
The development of thermotolerance in bone marrow CFU-S during chronic hyperthermia.
The purpose of this investigation was to study the response of the hematopoietic stem cell, spleen colony-forming unit (CFU-S), to hyperthermia. We have shown that CFU-S can acquire a transient resistance to further heating (thermotolerance). Hyperthermia was applied in vitro to nucleated bone marrow cells in McCoy's 5A medium plus 15% fetal bovine serum. ⋯ The thermotolerance ratio (TTR, ratio of the surviving fraction of the maximum thermotolerant cells to that of the normotolerant cells) was 2.1. Both the higher inactivation enthalpy for exposures less than 43 degrees C and the rapid increase in survival during the "step-up" heating experiments at 42 degrees C demonstrate that CFU-S can develop thermotolerance during prolonged hyperthermia. These results suggest that thermotolerance can influence the thermal response of pluripotent bone marrow stem cells heated during whole-body or local-regional clinical hyperthermia protocols.