Antioxidant supplementation had positive effects in old rat muscle, but through better oxidative status in other organs.
OBJECTIVE
Aged muscle is characterized by a defect in the ability of leucine to stimulate protein synthesis. We showed previously that antioxidant supplementation improved the anabolic response to leucine of old muscle and reduced inflammation. The aim of the present study was to determine if the positive effects observed in muscle could be related to an improvement of local muscle oxidative status.


METHODS
Two groups of 20-mo-old male Wistar rats were supplemented or not with rutin, vitamin E, vitamin A, zinc, and selenium during 7 wk. We measured body weight, food intake, oxidative status in muscle and other tissues, gastrocnemius muscle proteolytic activities, and liver glutathione metabolism.


RESULTS
Antioxidant supplementation had no effect on muscle antioxidant capacity, superoxide dismutase activities, and myofibrillar protein carbonyl content and induced an increase in muscle cathepsin activities. In other tissues, antioxidant supplementation increased liver glutathione (reduced plus oxidized glutathione) content, reduced oxidative damage in the liver and spleen (as measured by γ-keto-aldehyde content), and reduced heart thiobarbituric acid-reactive substances.


CONCLUSIONS
Our results showed that the positive effects of antioxidant supplementation observed previously on the anabolic response to leucine of old muscle were not directly related to an improvement of in situ muscle oxidative status. It could result from reduced systemic inflammation/oxidative stress. The dialog between muscle and other organs should be studied more thoroughly, especially during aging.
Mosoni
Laurent
L
INRA, UMR 1019 Nutrition Humaine, Saint Genès Champanelle, France. laurent.mosoni@clermont.inra.fr
Balage
Michèle
M
Vazeille
Emilie
E
Combaret
Lydie
L
Morand
Christine
C
Zagol-Ikapitte
Irène
I
Boutaud
Olivier
O
Marzani
Barbara
B
Papet
Isabelle
I
Dardevet
Dominique
D
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D002403:Cathepsins / Q000378:metabolism; D019587:Dietary Supplements; D005978:Glutathione / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009210:Myofibrils / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010447:Peptide Hydrolases / Q000378:metabolism; D050050:Protein Carbonylation; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D013482:Superoxide Dismutase; D002403:Cathepsins; D010447:Peptide Hydrolases; D005978:Glutathione