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Abstract
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Cardiotoxicity and oxidative stress is a life-threatening side effect of doxorubicin (DOX). We investigate the effects of short-term exercise as therapeutic tool for improvement of cardioprotection against DOX-induced cardiotoxicity in the rat. Methods Wistar males (weighing 257±28 g) were divided into six groups:(1) control+ placebo (2) control+ DOX 10 mg. kg-1 (3) control+ DOX 20mg. kg-1 (4) training+ placebo (5) training+ DOX10 mg. kg-1 (6) training+ DOX 20mg. kg-1. Cardiotoxicity was induced by DOX (10 and 20 mg. kg-1). The rats in groups 4, 5 and 6 experienced treadmill running of 25 to 39 min. day-1 and 15 to 17 m. min-1, 5 days/wk for 3 wk. At the end of the endurance training program, rats in the 1 and 4 groups, in the 2 and 5 groups and in the 3 and 6 groups received saline solution, DOX 10 mg. kg-1 and DOX 20 mg. kg-1, respectively. Result DOX administration (10 and 20 mg. kg-1) caused significant increase in MDA and Apelin, an insignificant increase in NO and a significant decrease in SOD, as compared to the C+ P group. Three weeks of the pretreatment endurance exercise resulted in a significant increase of Apelin and SOD, an insignificant increase of NO and an insignificant decrease of MDA, as compared to the C+ P group. Furthermore, after three weeks of endurance training and DOX treatment with 10mg. kg-1 and 20mg. kg-1, a significant increase in apelin and SOD, and a significant decrease in MDA were detected in comparison to C+ DOX10 and/or C+ DOX20 groups. There was a significant difference between DOX10 mg. kg-1 and DOX20 mg. kg-1 treatments in MDA levels only. Conclusion Pretreatment exercise may improve myocardial tolerance to DOX-induced cardiotoxicity by inhibition of oxidative stress and upregulation of antioxidants in heart tissue.
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