Oxidants differentially regulate the heat shock response.

Cells, animals, and humans respond to hyperthermia through the synthesis of a family of proteins termed heat shock proteins (HSPs). Because hyperthermic stress may also result in mitochondrial uncoupling and the generation of reactive oxygen species, we wondered whether oxidant stress was sufficient to increase cellular levels of HSP70. HSP70 was detected in cells heated or treated with menadione but not in those treated with hydrogen peroxide or xanthine/xanthine oxidase. We speculate that oxidant stress from menadione exposure is qualitatively different from exposure from hydrogen peroxide or xanthine/xanthine oxidase.