Whole body hyperthermia in mice confers heat shock protein-dependent radioresistance of their bone marrow and thymocytes

Here we studied how whole body hyperthermia in mice affects radiosensitivity of their tissues and cells. To examine a contribution of heat shock proteins (Hsps) we used Quercetin, an inhibitor of the Hsp induction. Bone marrow and thymocytes did become more radioresistant in heat-preconditioned mice. The radioprotection was well manifested in 18-26 h after hyperthermia and was strongly suppressed in Quercetin-injected mice. The revealed correlation between the intracellular Hsp content and radioresistance suggests the radioprotective potential of stress-inducible Hsps. Thus, our finding points out new ways for artificial modulation of the in vivo radiation effects by manipulating the Hsp expression.