KARDÄ°YORESPÄ°RATUVAR EGZERSÄ°Z TESTLERÄ° ... - Spor Bilim

7.ULUSLARARASI SPOR BİLİMLERİ KONGRESİ27-29 EKİM 2002KONGRE - PANELLEREXERCISE AND STRESS PROTEINSHisashi NaitoJuntendo University, Department of Exercise Physiology, School of Health and Sports Science, Inba, Chiba, Japan.The organism has various defense mechanisms for the stress. In the cellular level, some kinds of proteinsare rapidly synthesized for the stress and the homeostasis is maintained. The proteins are widely called thestress proteins. The term ―heat shock proteins (HSPs)‖ is also used because elevated temperatures (termedheat shock) was one of the first stressors applied. HSPs can be divided into several groups based upon theirmolecular masses, and to date, five separate families of HSPs have been identified. Of particular interest is theinducible form of the 70kDa family of HSPs (HSP72). HSP72 facilitates folding of proteins and is important in therepair of damaged proteins 4) . The expression of the HSP72 is controlled by intracellular HSF (Heat Shocktranscription Factor) and the production of HSP72 in cells is dependent upon both the intensity and duration ofthe stressor.Figure 1. HSP70 regulation and its rolesA large volume of research indicates that HSPs play an important physiological role in both the normaland stressed cell and that elevated cellular levels of HSP72 provide protection against potentially lethal stressessuch as hyperthermia, metabolic inhibitions, ischemia, oxidative stress, and so on. Recent investigationsindicate that the physiological stress associated with both acute and chronic exercise is also a stressor that iscapable of inducing HSP72 expression in various tissues (heart, skeletal muscles, adrenal, livers, etc) 3)6)8) .Though the mechanism is still unclear, many factors, e.g. generation of active oxygen species, increase of lacticacid and acidosis, glycogen depletion, elevation of body temperature, and mechanical stress, contribute directlyand indirectly to induce HSPs during exercise. In skeletal muscles, especially, protein synthesis is enhancedbecause of muscle hypertrophy and then HSP72 is necessary to assist in the assembly of myofibrillar proteins.Therefore, HSP72 is expected to be very important in the response to physical exercise and training. And now334