Heat shock protein 72 response to exercise in humans.

Heat shock protein (Hsp) 72 is a unique, ubiquitous molecule. In vitro and in vivo animal models have shown that increased Hsp 72 is associated with improved cellular survivability and tolerance to stressors. The primary focus of this article is to review the Hsp 72 protein response to exercise in humans. Various mechanisms regulate post-transcriptional activity and therefore measurement of messenger RNA (mRNA) does not necessarily represent the level of functional Hsp 72. For this reason, this article incorporates only a few studies that assessed Hsp 72 mRNA response to exercise. Although this article focuses on human studies, it also includes some key animal studies to provide insight into the mechanisms of the response of Hsp 72 to stress.Intra- (IC) and extracellular (EC) Hsp 72 have different functions. IC Hsp 72 confers cellular protection from subsequent stressors, while EC Hsp 72 has a whole-body systemic role in antigen presentation and immunity. An acute exercise bout stimulates an increase in both IC and EC Hsp 72. Long-term training and improved fitness increases the rate of availability of IC Hsp 72 in response to stress. Other factors that affect Hsp 72 production include environmental factors, exercise mode, duration and intensity, age, estrogen, and anti-oxidant and glycogen availability. The functions and roles of Hsp 72 also depend on the tissue of origin. This article describes the Hsp 72 response to exercise in relation to the tissue assayed (i.e. skeletal muscle vs lymphocyte) and the origin of the sample (i.e. venous vs arterial serum). Collectively, the reviewed studies reveal exciting and novel research that encourages future investigation in this area.