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EFFECTS OF ENDURANCE TRAINING ON SUPEROXIDE DISMUTASE ACTIVITY, CONTENT AND mRNA EXPRESSION IN RAT MUSCLE #
Author(s) -
Ohishi S.,
Kizaki T.,
Nagasawa J.,
Izawa T.,
Komabayashi T.,
Nagata N.,
Suzuki K.,
Taniguchi N.,
Ohno H.
Publication year - 1997
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1997.tb01196.x
Subject(s) - superoxide dismutase , messenger rna , endocrinology , chemistry , endurance training , dismutase , medicine , andrology , biology , antioxidant , biochemistry , gene
SUMMARY 1. The purpose of the present study was to investigate the changes in superoxide dismutase (SOD) isoenzyme (Mn 2+ ‐SOD and Cu 2+ , Zn 2+ ‐SOD) activities, contents and mRNA expressions in rat skeletal muscle during endurance training and a single bout of exercise. 2. Thirty‐eight male Wistar rats were divided into untrained (U) and trained (T) groups. The T group rats were treadmill‐trained for 9 weeks. The activity, content and mRNA expression of Mn 2+ ‐SOD and Cu 2+ , Zn 2+ ‐SOD were determined in the soleus muscle of each rat. 3. Mn 2+ ‐SOD activity and content in the T group were significantly higher than in the U group, both at rest (22 and 21%, respectively) and after exercise (24 and 46%, respectively), while a single bout of exercise affected neither the activity nor content of Mn 2+ ‐SOD in either group. 4. The content of Cu 2+ , Zn 2+ ‐SOD in both groups was not different at rest and after exercise, although its activity at rest was significantly higher in the T group than in the U group (by 29%). 5. After exercise, the expression of Mn 2+ ‐SOD mRNA was markedly attenuated only in the U group (49%); the expression of Cu 2+ , Zn 2+ ‐SOD mRNA was not influenced by exercise. 6. Our results suggest that adequate endurance training increases both the activity and content of Mn 2+ ‐SOD and that untrained rats are rather susceptible to oxidative stress during physical exercise. It thus appears that Mn 2+ ‐SOD provides a reliable index of physical training. 7. The results obtained in the present study also suggest that muscle has the capacity of responding to training in such a manner as to reduce the potential harm arising from the accumulation of oxygen free radicals resulting from enhanced metabolic activity.