Effect of spontaneous exercise on antioxidant capacity in rat muscles determined by electron spin resonance.
OBJECTIVE
The effect of physical activity on antioxidant capacity in muscle remains unknown. This study investigated the effect of spontaneous exercise on antioxidant capacity in rat muscles determined by electron spin resonance (ESR), which is a technique for the direct detection of free radicals.


METHODS
Ten-week-old male Wistar rats were housed individually in cages with a running wheel. Rats were classified as high activity (HA), middle activity (MA) or low activity group (LA), based on an assessment of running distance covered over a 23-week period. After 23 weeks of housing, soleus (Sol), plantaris (Pl), gastrocnemius [deep/surface portions (GasD/GasS)] and heart (Hrt) muscles were isolated, and scavenging activity against superoxide anions (O(2)(*-)) and hydroxyl radicals (HO(*)) was determined by ESR using a spin-trap chemical. The citrate synthase (CS) activity was used as a marker of mitochondrial oxidative phosphorylation capacity.


RESULTS
Among the parameters measured, only O(2)(*-) scavenging activity in GasD significantly correlated with the running distance. The highest scavenging activity was observed in Hrt of HA rats. The O(2)(*-) scavenging activity in Pl of MA rats was significantly higher than that of LA rats. The O(2)(*-) scavenging activity of Sol and GasS was not significantly different between the three groups. Furthermore, the HO(*) scavenging activity of any muscle specimens was similar among the three groups and did not correlate with running distance at all. CS activity did not significantly differ between the three groups.


CONCLUSIONS
These data suggest that O(2)(*-) scavenging activity in specific types of muscle tissues would increase especially in spontaneously active animals. However, HO(*) scavenging activity would not.
Tanabe
K
K
Laboratory of Advanced Research D, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan. kai-tanabe@wellness.taiiku.tsukuba.ac.jp
Masuda
K
K
Hirayama
A
A
Nagase
S
S
Kono
I
I
Kuno
S
S
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001835:Body Weight / Q000502:physiology; D004435:Eating / Q000502:physiology; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D005082:Physical Exertion / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
D000975:Antioxidants; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D013481:Superoxides; D017665:Hydroxyl Radical