Aerobic Exercise Attenuates Kidney Injury, Improves Physical Performance, and Increases Antioxidant Defenses in Lungs of Adenine-Induced Chronic Kidney Disease Mice

The association between chronic kidney disease (CKD) and pulmonary pathophysiological changes is well stablished. Nevertheless, the effects of aerobic exercise (AE) on lungs of CKD need further clarification. Thus, Swiss mice were divided in control, AE, CKD, and CKD + AE groups. CKD was induced by 0.2% adenine intake during 8 weeks (4 weeks of CKD induction and 4 weeks of AE). AE consisted in running on treadmill, at moderate intensity, 30 min/day, 5 days/week, during 4 weeks. Twenty-four hours after the last training day, functional capacity test was performed, and 48 h after the test, mice were euthanized. CKD mice showed a significant increase in urine output, serum urea, and creatinine concentrations, and decreased body weight and urine density, besides oxidative damage (p = 0.044), edema area (p < 0.001), leukocyte infiltration (p = 0.040), and collagen area in lung tissue (p = 0.004). AE resulted in an increase of distance traveled (p = 0.049) and maximum speed (p = 0.046), increased activity of catalase (p = 0.031) and glutathione peroxidase (p = 0.048) in lungs, increased levels of nitric oxide (NOx) in serum (p = 0.001) and bronchoalveolar lavage fluid (p = 0.047), and decreased kidney histological injury (p = 0.018) of CKD mice. However, AE also increased oxidative damage (p = 0.003) and did not change collagen content or perivascular edema in lungs (p > 0.05) of CKD mice. Therefore, AE attenuated kidney injury and improved antioxidants defenses in lungs. Despite no significant changes in pulmonary damage, AE significantly improved physical performance in CKD mice.