Does heat contribute to the exercise-induced production of HSPs in human skeletal muscle?
• James P Morton, Lecturer and Post-Doctoral Researcher in Exercise Physiology Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK Dear Editor Ogura et al. [1] demonstrated that microwave hyperthermia treatment increases HSP27, HSP72 and HSP90 content of human skeletal muscle. We have also employed a passive heating protocol entailing submersion of one limb (to the level of the gluteal fold) in warm water maintained at approximately 45°C [2]. Our protocol induced an increase in muscle temperature to 39.5°C and we failed to observe any increase in alpha B-crystallin, HSP27, HSP60, HSC70 or HSP70 in the vastus lateralis muscle at 48 h post-heating [2]. We therefore suggested that elevations in muscle temperature per se appear not to be the most important stressor that induces up-regulation of heat shock proteins (HSPs) following exercise. In this regard and given that antioxidants abolish the exercise-induced stress response, we also suggested that ex
