Potential sources of oxidative stress that induce postexercise proteinuria in rats

• Published in: Journal of applied physiology (1985) Vol. 104; no. 4; pp. 1063 - 1068
• Main Authors: Kocer, Gunnur, Senturk, Umit Kemal, Kuru, Oktay, Gunduz, Filiz
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01-04-2008; American Physiological Society
• Subjects: Animals; Biological and medical sciences; Enzyme Inhibitors - pharmacology; Enzymes; Exercise; Female; Fundamental and applied biological sciences. Psychology; Kidney - metabolism; Kidneys; Medical disorders; NADPH Oxidases - metabolism; Oxidation; Oxidative Stress - physiology; Oxypurinol - pharmacology; Physical Conditioning, Animal - adverse effects; Physical Conditioning, Animal - physiology; Protein Carbonylation - drug effects; Protein Carbonylation - physiology; Proteins; Proteinuria - etiology; Proteinuria - metabolism; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances - metabolism; Xanthine Oxidase - antagonists & inhibitors; Xanthine Oxidase - metabolism; Phosphates; Oxidative stress; Reactive oxygen species; Urinary system disease; Rat; Enzyme; Rodentia; Adenine; B-Vitamins; Vertebrata; Mammalia; Stress proteinuria; Xanthine oxidase; Nicotinamide; Oxidoreductases; nicotinamide adenine dinucleotide phosphate oxidase
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00581.2007

1 Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya; and 2 School of Health Sciences, Mugla University, Mugla, Turkey
Submitted 31 May 2007
; accepted in final form 5 February 2008
Exercise-induced proteinuria is a common consequence of physical activity and is caused predominantly by alterations in renal hemodynamics. Although it has been shown that exercise-induced oxidative stress can also contribute to the occurrence of postexercise proteinuria, the sources of reactive oxygen species that promote it are unknown. We investigated the enzymes nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and xanthine oxidase (XO) as possible sources of oxidative stress in postexercise proteinuria. First, we evaluated the effect of blocking the NADPH oxidase enzyme on postexercise proteinuria. We found a significant increase in urinary protein level, kidney thiobarbituric acid-reactive substances (TBARS), and protein carbonyl content after exhaustive exercise, and NADPH oxidase activity was induced by exercise. Rats that were treated with an NADPH oxidase inhibitor for 4 days before exhaustive exercise showed no increase in kidney TBARS or protein carbonyl derivative level and no proteinuria or NADPH oxidase activation. In the next set of experiments, we investigated the effect of XO blockage on postexercise proteinuria. Oxypurinol, an XO inhibitor was administered to rats for 3 days before exercise. Although XO inhibition significantly decreased kidney TBARS levels and protein carbonyl content in exercised rats, the inhibition did not prevent exercise-induced proteinuria. However, plasma and kidney XO activity was not induced by exercise, but rather it was suppressed under oxypurinol treatment. These results suggest that increased NADPH oxidase activity induced by exhaustive exercise is an important source of elevated oxidative, stress during exercise, which contributes to the occurrence of postexercise proteinuria.
xanthine oxidase; nicotinamide adenine dinucleotide phosphate oxidase; reactive oxygen species
Address for reprint requests and other correspondence: Ü. K. entürk, Akdeniz Univ., Medical Faculty, Dept. of Physiology, Kampus, 07070 Antalya, Turkey (e-mail: uksenturk{at}akdeniz.edu.tr )