Antioxidant enzyme systems in rat liver and skeletal muscle. Influences of selenium deficiency, chronic training, and acute exercise.
The influences of selenium deficiency (Se-D), chronic training, and an acute bout of exercise on hepatic and skeletal muscle antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX), as well as glutathione S-transferase (GST) and tissue lipid peroxidation, were investigated in post-weaning male Sprague-Dawley rats. Se-D per se depleted GPX in both liver and skeletal muscle but had no effect on SOD or catalase activity. One hour of treadmill running (20 m/min, 0% grade and 27 m/min, 15% grade for untrained and trained rats, respectively) significantly elevated hepatic catalase and cytosolic SOD activity; more prominent activations were found in the Se-D or untrained rats, whereas skeletal muscle antioxidant enzymes were little affected. Ten weeks of training (1 h/day, 5 days/week at 27 m/min, 15% grade) increased hepatic mitochondrial SOD by 23% (P less than 0.05) in Se-D rats. Both hepatic mitochondrial and cytosolic GPX were decreased by training whereas GPX was increased twofold in skeletal muscle mitochondria. Se-independent GPX was elevated by training only in the skeletal muscle mitochondria of Se-D rats. Lipid peroxidation (malondialdehyde formation) was increased by an acute bout of exercise in hepatic mitochondria of the untrained rats and in skeletal muscle mitochondria of the Se-D rats. These data indicate that antioxidant enzymes in liver and skeletal muscle are capable of adapting to selenium deficiency and exercise to minimize oxidative injury caused by free radicals.
Ji
L L
LL
Institute for Enzyme Research, University of Wisconsin, Madison 53705.
Stratman
F W
FW
Lardy
H A
HA
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001835:Body Weight; D002374:Catalase / Q000378:metabolism; D004435:Eating; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008297:Male; D009132:Muscles / Q000201:enzymology*; D010805:Physical Conditioning, Animal; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains; D012643:Selenium / Q000172:deficiency*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D008054:Lipid Peroxides; D013438:Sulfhydryl Compounds; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D012643:Selenium