Influence of nutrient and energy deprivation on cellular response to single and fractionated heat treatments.

The effect of hypoglycemia and hypoxia on cell survival following single and fractionated 44 degrees C heat treatments was investigated. These studies show that short-term glucose deprivation or oxygen deprivation does not increase sensitivity to single or fractionated heat treatments compared to normal nutrient conditions. However, simultaneous hypoglycemia and hypoxia leads to an increased sensitivity to single heat treatments, and to an even greater increase in sensitivity to fractionated heat treatments. Sensitivity to heat treatment under nutrient-deprived conditions correlates with intracellular ATP levels at the time of treatment. These data indicate that it is not nutrient concentration per se, but rather the effect of nutrient level on intracellular ATP concentration that affects thermal sensitivity.