Pretreatment Effect of Running Exercise on HSP70 and DOXInduced Cardiotoxicity

Objective: The purpose of this study was to determine pretreatment effects of moderate-term endurancetraining before the various dosages (10 and 20 mg.kg_1) of DOX on a heat shock protein (HSP70kda) and cardiotoxicityin heart tissue.
Methods: Forty-eight male rats were randomly assigned to nontraining (NT) and training (T)groups and three subgroups; DOX10mg.kg-1 and DOX20mg.kg-1 and saline treatment. The training program includedtreadmill running between 25-39 min/day and 15-17 m/min, 5 days/wk for 3 wk.
Result: DOX administration, inparticularly with 20mg.kg_1, caused up-regulation of oxidants and cardiac damage (MDA, CK, CPK-MB and CK/CPK-MB) and down-regulation of cardioprotection (HSP70, SOD) markers, as compared to NT+saline group.Pretreatment effect of treadmill running endurance exercise in the presence of DOX with 10 mg.kg_1 caused asignificant increase in HSP70, SOD and a significant decrease in MDA and insignificant decrease in CK, CPK-MBand CK/CPK-MB, in comparison T+DOX10 with NT+DOX10 group. However, there was no significant differencebetween T+DOX10mg.kg_1 and T+DOX20mg.kg_1 in the aforesaid markers.
Conclusion: Dox-induced cardiotoxicity isrelated to oxidative stress. Our study suggests that pretreatment with endurance exercise may be considered as apotentially useful strategy to improve myocardial tolerance against single dose DOX-induced oxidative damage.