Implication of xanthine oxidase in muscle oxidative stress in COPD patients.
OBJECTIVE
The aim of this study was to determine the implication of xanthine oxidase (XO) in the exercise-induced muscle oxidative stress and muscle dysfunction of these patients.


METHODS
A randomized, crossover and double-blind study was conducted in nine severe COPD patients, who performed a localized quadriceps endurance test after oral treatment with allopurinol, a XO inhibitor or placebo. Redox status was studied in arterial and venous femoral blood before and after the endurance test.


RESULTS
In placebo condition, muscle exercise resulted in a significant increase in AOPP and isoprostanes, with a significant increase in the venoarterial difference (v-a) in isoprostanes after exercise as compared with before (p<0.05). In contrast, allopurinol treatment prevented the elevation in AOPP levels and v-a isoprostanes after exercise. However, no significant improvement in quadriceps muscle endurance was observed, but allopurinol treatment seemed to preserve muscle strength properties.


CONCLUSIONS
This study demonstrates that XO is implicated in the exercise-induced muscle oxidative stress of COPD patients. Allopurinol administration seemed to improve only some muscle properties. Therefore other sources of muscle oxidative stress should be implicated in muscle dysfunction observed in these patients.
Delample
Delphine
D
INSERM ERI25 'Muscle and Pathologies', Université Montpellier I, Montpellier, France. ddelample@yahoo.fr
Durand
Fabienne
F
Severac
Arnold
A
Belghith
Monia
M
Mas
Emilie
E
Michel
Francoise
F
Cristol
Jean-Paul
JP
Hayot
Maurice
M
Prefaut
Christian
C
D000284:Administration, Oral; D000368:Aged; D000493:Allopurinol / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000201:enzymology* / Q000378:metabolism; D018384:Oxidative Stress; D010919:Placebos; D029424:Pulmonary Disease, Chronic Obstructive / Q000201:enzymology* / Q000378:metabolism; D052097:Quadriceps Muscle / Q000473:pathology; D014969:Xanthine Oxidase / Q000502:physiology*
D004791:Enzyme Inhibitors; D010919:Placebos; D000493:Allopurinol; D014969:Xanthine Oxidase