Oxidative stress in hemodialyzed patients during exhausting exercise.
BACKGROUND
This study was designed to study the effect of an exhausting exercise test on plasma lipid peroxidation marker (malondialdehyde, MDA) and on vitamin E levels in hemodialyzed patients (HD) compared to healthy control subjects (HC).


METHODS
Eight sedentary chronically HD, (39.0+/-10.8 years) and eight sedentary HC (38.4+/-12.4 years) were studied. Before exercise, the activity of scavenger enzymes [plasma and erythrocyte glutathione peroxidase (GPX), and erythrocyte superoxide dismutase (SOD)] was determined. All subjects performed a symptom-limited exercise test; respiratory gas exchanges were collected on-line and blood was sampled five min before exercise, at exhaustion and after 30 min of recovery.


RESULTS
At rest, the activity of plasma and erythrocyte GPX and erythrocyte SOD was significantly lower in HD than in HC. Exercise provoked an increase of plasma MDA concentration after recovery in HD patients, whereas our HC group show a decrease in MDA plasma level immediately after exercise, returning to the rest values during recovery. Exercise induced no change of vitamin E concentration in HD whereas in HC it increased during recovery.


CONCLUSIONS
Our results indicate that: 1) at rest: although hemodialyzed patients showed lower scavenger enzymes activity than HC subjects, there was no difference in MDA plasma level between groups; 2) there is some evidence that physical exercise contribute to oxidative stress during recovery in HD patients, and 3) exercise induced an increase in plasma vitamin E concentration in healthy subjects.
Jiménez
L
L
Département de Physiologie de la Faculté de Médecine Cochin-Port-Royal (Université René Descartes) and Service d'Explorations Fonctionnelles et de Physiopathologie de l'Exercise Centre Hospitalier Cochin-Tarnier, Paris, France. Lijimenez@aol.com
Lefèvre
G
G
Richard
R
R
Couderc
R
R
Saint George
M
M
Duvallet
A
A
Rieu
M
M
D000328:Adult; D015415:Biomarkers / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology*; D006435:Renal Dialysis / Q000009:adverse effects*; D018709:Statistics, Nonparametric; D013482:Superoxide Dismutase / Q000097:blood; D014810:Vitamin E / Q000097:blood
D015415:Biomarkers; D014810:Vitamin E; D008315:Malondialdehyde; D013482:Superoxide Dismutase