Superoxide dismutase gene expression in skeletal muscle: fiber-specific adaptation to endurance training

1 Department of Kinesiology and Interdisciplinary Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706; and 2 Department of Hygiene, National Defense Medical College, Saitama 359, Japan The effects of endurance training on the enzyme activity, protein content, and mRNA abundance of Mn and CuZn superoxide dismutase (SOD) were studied in various phenotypes of rat skeletal muscle. Female Sprague-Dawley rats were randomly divided into trained (T, n = 8) and untrained (U, n = 8) groups. Training, consisting of treadmill running at 27 m/min and 12% grade for 2 h/day, 5 days/wk for 10 wk, significantly increased citrate synthase activity ( P