Expression of serum HSP27 under exercise-induced muscle damage in elite greco-roman wrestlers

Abstract

The effectiveness of physical training depends on the training load, the individual toleration ability and an imbalance between the two may lead to under or over-training. One of the unique features of an exercise is that it leads to a simultaneous increase of antagonistic mediators. On the one hand, exercise elevates catabolic molecules such as stress hormo nes, pro-inflammatory cytokines etc. On the other hand, exercise stimulates anabolic components such as heat shock proteins (HSPs) which protect against stressors. If the anabolic response is stronger, exercise will probably lead ultimately to an increased muscle mass and exercise adaptation [1,2]. HSPs represent cell-protective system that may be induc ed by reactive oxygen/nitrogen species (RO/NS). Under phy sio logical conditions, constitutively expressed HSPs function as molecular chaperones, whereas under metabolic stress, HSPs protect proteins against misfolding, aggregation and denaturation. In addition, HSPs may directly regulate specific stress-responsive signalling pathways and may antagonize signalling cascades that result in apoptosis [3,2]. Exerciseinduced stress and muscle damage is considered to be one of the stimulus which induce HSPs [4]. HSPs increase the stress tolerance and participate in the cellular repair process during overtraining. Among the subset of stress-responsive proteins, evaluation of HSP27 level is considered to be a new approach to monitoring exercise training and adaptive mechanisms [5]. Currently, reactive oxygen/nitrogen species NO and H2O2 are perceived as important signalling molecules generated during muscle contraction and involved in the regeneration and adaptation of skeletal muscle to physical work [6]. NO