ORIGINAL RESEARCH Physical Exercise Prevents the Exacerbation of Oxidative Stress Parameters in Chronic Kidney Disease Ba ´rbara L. P. Coelho, MSc, Luı ´s G. C. Rocha, BSc, Karoline S. Scarabelot, BSc, De´bora L. Scheffer, BSc, Merieli M. Ronsani, BSc, Paulo C. L. Silveira, MSc, Luciano A. Silva, MSc, Cla ´udio T. Souza, PhD, and Ricardo A. Pinho, PhD Objective: Reactive oxygen species play an important role in the pathogenesis of chronic kidney disease (CKD). Physical exercise was suggested as a useful approach to diminish impaired oxidative defense mechanisms. This study sought to observe the effects of physical training before the induction of renal lesions on oxidative stress parameters in animals induced for CKD. Methods: Twenty-four male Wistar rats were divided into four groups (n 5 6): sham, sham plus exercise, CKD, and CKD plus exercise. Exercise groups performed physical training on a treadmill for 8 weeks (up to 1 km/h for 50 min/ day, 5 days/week). Forty-eight hours after the final exercise session, a surgical reduction of renal mass was per- formed (5/6 nephrectomized). Thirty days later, blood samples were collected to determine serum creatinine and urea concentrations, and the right kidney was surgically removed and stored at 270  C for later analysis of superox- ide production, antioxidant enzymes (superoxide dismutase and catalase), and oxidative damage of lipids (thiobar- bituric acid reactive susbstances level) and proteins (carbonyl groups and sulfhydryl content). Results: A significant increase occurred in creatinine and urea levels, superoxide production, antioxidant enzymes, and oxidative damage in the CKD group, compared with sham-treated animals (P , .05). Physical training prevented superoxide production, and decreased the oxidative damage in the CKD group (P , .05), but did not increase the effect of antioxidants. Conclusion: Physical training before induction of a renal lesion is capable of improving oxidative damage param- eters and oxidant production, without altering renal function and the antioxidant defense system. Ó 2009 by the National Kidney Foundation, Inc. All rights reserved. K IDNEY DISEASE is a serious and prevalent health problem, and it exerts a significant impact on a patient’s short-term and long-term sur- vival. The pathophysiological spectrum of kidney diseases is broad. 1 Chronic kidney disease (CKD) is characterized by a progressive loss of nephrons caused by increased intraglomerular pressure and hyperfiltration. 2 Although the biochemical basis of CKD complications is mostly known, the patho- genesis of kidney disease in molecular and biochem- ical terms remains to be fully elucidated. 3 Chronic kidney disease is accompanied by very complex long-term manifestations, such as acceler- ated aging, atherosclerosis, heart disease, polyneuro- pathies, and amyloidosis, which may be related to the increased production of free radicals. 4 Recent experimental evidence indicates that reactive oxygen species (ROS) play a key role in the patho- physiological pathways of a wide variety of clinical and experimental renal diseases. 5,6 This finding is especially relevant for the kidney, in which a spec- trum of seemingly unrelated disorders, from Exercise Biochemistry and Physiology Laboratory, Postgraduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciu ´ma, Santa Catarina, Brazil. Address reprint requests to Ricardo A. Pinho, PhD, Exercise Bio- chemistry and Physiology Laboratory, Postgraduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Av. Universita ´ria 1105, Bairro Universita ´rio, 88806- 000 Criciu ´ma, Santa Catarina, Brazil. E-mail: pinho@unesc.net Ó 2009 by the National Kidney Foundation, Inc. All rights reserved. 1051-2276/09/-0--0000$36.00/0 doi:10.1053/j.jrn.2009.10.007 Journal of Renal Nutrition, Vol -, No - (-), 2009: pp 1–7 1 ARTICLE IN PRESS